https://github.com/rajeevranjancom/leetcode_java
Leetcode Java Solution and Documentation
https://github.com/rajeevranjancom/leetcode_java
java java-8 javadoc-documentation javadoc-links leetcode-java leetcode-solutions oracle
Last synced: 9 months ago
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Leetcode Java Solution and Documentation
- Host: GitHub
- URL: https://github.com/rajeevranjancom/leetcode_java
- Owner: rajeevranjancom
- License: gpl-3.0
- Created: 2020-09-20T17:39:12.000Z (about 5 years ago)
- Default Branch: master
- Last Pushed: 2020-10-19T05:41:55.000Z (about 5 years ago)
- Last Synced: 2025-01-22T10:36:42.953Z (11 months ago)
- Topics: java, java-8, javadoc-documentation, javadoc-links, leetcode-java, leetcode-solutions, oracle
- Language: Java
- Homepage: https://www.javatpoint.com/java-tutorial
- Size: 1.06 MB
- Stars: 0
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# Leetcode_Java@Rajeev Ranjan
# Solution@Leetcode
## Links:
| Websites |
|---------------|
| https://docs.oracle.com/en/java/ (Java Documentation) |
| https://docs.oracle.com/en/java/javase/15/ (JDK 15 Documentation) |
| https://docs.oracle.com/javacomponents/ (Java Components) |
| https://docs.oracle.com/javaee/7/index.html (Java Platform, Enterprise Edition (Java EE) 7) |
| https://docs.oracle.com/javame/8.3/index.html (Java Platform, Micro Edition Embedded (Java ME Embedded) 8.3) |
| https://docs.oracle.com/javase/8/javase-embedded.htm (Java Platform, Standard Edition (Java SE) 8) |
| https://docs.oracle.com/en/java/javacard/3.1/ (Java Card 3.1 Documentation) |
| https://docs.oracle.com/en/java/javacard/3.1/books.html (Release Notes and Books) |
| https://docs.oracle.com/en/java/javase/15/docs/api/index.html (Java® Platform, Standard Edition & Java Development Kit
Version 15 API Specification) |
| https://www.java.com/ES/download/ (Java Download) |
| https://www.oracle.com/in/java/technologies/javase-downloads.html (Java SE Downloads) |
## Notes:
| Important |
|------------------|
| Java is a set of computer software and specifications developed by James Gosling at Sun Microsystems, which was later acquired by the Oracle Corporation, that provides a system for developing application software and deploying it in a cross-platform computing environment |
| Initial release date: 23 January 1996 |
| Developed by: Sun Microsystems |
| Original author(s) James Gosling, Sun Microsystems |
| Developer(s) Oracle Corporation |
| Operating system Microsoft Windows, Solaris, Linux, macOS |
| Platform IA-32, x64, ARMv7, ARMv8, SPARC (up to Java 14) (Java 8 includes 32-bit support – while no longer supported freely by Oracle for commercial use – 32- bit platforms are not supported in other versions, since dropped officially in Java 10.) |
| Available in English, Chinese, French, German, Italian, Japanese, Korean, Portuguese, Spanish, Swedish |
## Table:
| Question | Solution | Difficulty | Tag |
|------------------------------------------------------------------------------------------------------------------------------------------------------------|:---------------------------------------------------------------------------------------------------------------------------------:|:----------:|:----------:|
| [1. Two Sum](https://leetcode.com/problems/two-sum/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/001_Two_Sum.java) | Easy | Array / Hash Table |
| [2. Add Two Numbers](https://leetcode.com/problems/add-two-numbers/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/002_Add_Two_Numbers.java) | Medium | Linked List |
| [3. Longest Substring Without Repeating Characters](https://leetcode.com/problems/longest-substring-without-repeating-characters/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/003_LongestSubstringWithoutRepeatingCharacters3.java) | Medium | Hash Table / Two Pointers |
| [4. Median of Two Sorted Arrays](https://leetcode.com/problems/median-of-two-sorted-arrays/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/004_Median_of_Two_Sorted_Arrays.java) | Hard | Array / Binary Search |
| [5. Longest Palindromic Substring](https://leetcode.com/problems/longest-palindromic-substring/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/005_Longest_Palindromic_Substring.java) | Medium | String |
| [6. ZigZag Conversion](https://leetcode.com/problems/zigzag-conversion/description/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/006_ZigZag%20Conversion.java) | Medium | String |
| [7. Reverse_Integer](https://leetcode.com/problems/reverse-integer/description/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/007_Reverse_Integer.java) | Medium | Math |
| [8. StringToInteger](https://leetcode.com/problems/longest-palindromic-substring/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/008_StringToInteger8.java) | Medium | String |
| [9. Palindrome Number](https://leetcode.com/problems/palindrome-number/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/009_Palindrome_Number.java) | Easy | Math |
| [10. Regular Expression Matching](https://leetcode.com/problems/regular-expression-matching/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/010_RegularExpressionMatching10.java) | Hard | String / Dynamic Programming / Backtracking |
| [11. Container With Most Water](https://leetcode.com/problems/container-with-most-water/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/011_ContainerWithMostWater11.java) | Medium | Medium | Array / Two Pointers |
| [12. Integer to Roman](https://leetcode.com/problems/integer-to-roman/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/012_IntegerToRoman12.java) | Medium | String |
| [13. Roman to Integer](https://leetcode.com/problems/roman-to-integer/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/013_RomanToInteger13.java) | Easy | String |
| [14. Longest Common Prefix](https://leetcode.com/problems/longest-common-prefix/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/014_LongestCommonPrefix14.java) | Easy | String |
| [15. 3Sum](https://leetcode.com/problems/3sum/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/015_ThreeSum15.java) | Medium | Array / Two Pointers |
| [16. 3Sum Closest](https://leetcode.com/problems/3sum-closest/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/016_ThreeSumClosest16.java) | Medium | Array / Two Pointers |
| [17. Letter Combinations of a Phone Number](https://leetcode.com/problems/letter-combinations-of-a-phone-number/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/017_LetterCombinationsOfAPhoneNumber17.java) | Medium | Backtracking / String |
| [18. 4Sum](https://leetcode.com/problems/4sum/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/018_FourSum18.java) | Medium | Array |
| [19. Remove Nth Node From End of List](https://leetcode.com/problems/remove-nth-node-from-end-of-list/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/019_Remove_Nth_Node_From_End_of_List.java) | Medium | Linked List / Two Pointers |
| [20. Valid Parentheses](https://leetcode.com/problems/valid-parentheses/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/020_ValidParentheses20.java) | Easy | Stack |
| [21. Merge Two Sorted Lists](https://leetcode.com/problems/merge-two-sorted-lists/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/021_MergeTwoSortedLists21.java) | Easy | Linked List |
| [22. Generate Parentheses](https://leetcode.com/problems/generate-parentheses/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/022_GenerateParentheses22.java) | Medium | String / Backtracking |
| [23. Merge k Sorted Lists](https://leetcode.com/problems/merge-k-sorted-lists/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/023_MergeKSortedLists23.java) | Hard | Linked List / Heap |
| [25. Reverse Nodes in k-Group](https://leetcode.com/problems/reverse-nodes-in-k-group/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/025_ReverseNodesInKGroup25.java) | Hard | Linked List |
| [26. Remove Duplicates from Sorted Array](https://leetcode.com/problems/remove-duplicates-from-sorted-array/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/026_RemoveDuplicatesFromSortedArray26.java) | Easy | Array / Two Pointers |
| [28. Implement strStr()](https://leetcode.com/problems/implement-strstr/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/028_ImplementStrStr28.java) | Easy | String |
| [29. Divide Two Integers](https://leetcode.com/problems/divide-two-integers/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/029_DivideTwoIntegers29.java) | Easy | String |
| [31. Next Permutation](https://leetcode.com/problems/next-permutation/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/031_NextPermutation31.java) | Medium | Array |
| [32. Longest Valid Parentheses](https://leetcode.com/problems/longest-valid-parentheses/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/032_LongestValidParentheses32.java) | Hard |
| [33. Search in Rotated Sorted Array](https://leetcode.com/problems/search-in-rotated-sorted-array/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/033_SearchInRotatedSortedArray33.java) | Medium | Array / Binary Search |
| [34. Search for a Range](https://leetcode.com/problems/search-for-a-range/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/034_SearchForARange34.java) | Medium | Array / Binary Search |
| [35. Search Insert Position](https://leetcode.com/problems/search-insert-position/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/035_SearchInsertPosition35.java) | Easy | Array / Binary Search |
| [36. Valid Sudoku](https://leetcode.com/problems/valid-sudoku/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/036_ValidSudoku36.java) | Medium | Hash Table |
| [37. Sudoku Solver](https://leetcode.com/problems/sudoku-solver/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/037_SudokuSolver37.java) | Hard | Hash Table |
| [39. Combination Sum](https://leetcode.com/problems/combination-sum/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/039_CombinationSum39.java) | Medium | String |
| [41. First Missing Positive](https://leetcode.com/problems/first-missing-positive/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/041_FirstMissingPositive41.java) | Hard | Array |
| [42. Trapping Rain Water](https://leetcode.com/problems/trapping-rain-water/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/042_TrappingRainWater42.java) | Hard | Array / Two Pointers / Stack |
| [43. Multiply Strings](https://leetcode.com/problems/multiply-strings/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/043_MultiplyStrings43.java) | Medium | String |
| [44. Wildcard Matching](https://leetcode.com/problems/wildcard-matching/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/044_WildcardMatching44.java) | Hard | String / Backtracking / Greedy |
| [45. Jump Game II](https://leetcode.com/problems/jump-game-ii/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/045_JumpGameII45.java) | Hard | Hard | Array / Greedy |
| [46. Permutations](https://leetcode.com/problems/permutations/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/046_Permutations46.java) | Medium | Backtracking |
| [47. Permutations II](https://leetcode.com/problems/permutations-ii/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/047_PermutationsII47.java) | Medium | Backtracking |
| [48. Rotate Image](https://leetcode.com/problems/rotate-image/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/048_RotateImage48.java) | Medium | Matrix | Hash Table / String |
| [49. Group Anagrams](https://leetcode.com/problems/group-anagrams/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/049_GroupAnagrams49.java) | Medium | Hash Table / String |
| [50. Pow(x, n)](https://leetcode.com/problems/powx-n/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/050_PowXN50.java) | Medium | Binary Search |
| [51. N-Queens](https://leetcode.com/problems/n-queens/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/051_NQueens51.java) | Hard | Binary Search |
| [52. N-Queens II](https://leetcode.com/problems/n-queens-ii/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/052_NQueensII52.java) | Hard | Binary Search |
| [53. Maximum Subarray](https://leetcode.com/problems/maximum-subarray/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/053_MaximumSubarray53.java) | Easy | Dynamic Programming / Array |
| [54. Spiral Matrix](https://leetcode.com/problems/spiral-matrix/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/054_SpiralMatrix54.java) | Medium | Array |
| [55. Jump Game](https://leetcode.com/problems/jump-game/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/055_JumpGame55.java) | Medium | Array / Greedy |
| [56. Merge Intervals](https://leetcode.com/problems/merge-intervals/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/056_MergeIntervals56.java) | Medium | Medium | Array / Sort |
| [57. Insert Interval](https://leetcode.com/problems/insert-interval/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/057_InsertInterval57.java) | Hard | Hard | Array / Sort |
| [59. Spiral Matrix II](https://leetcode.com/problems/spiral-matrix-ii/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/059_SpiralMatrixII59.java) | Medium | Array |
| [60. Permutation Sequence](https://leetcode.com/problems/permutation-sequence/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/060_PermutationSequence60.java) | Medium | Backtracking / Math |
| [61. Rotate List](https://leetcode.com/problems/rotate-list/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/061_AddBinary.java) | Medium | Linked List / Two Pointers |
| [62. Unique Paths](https://leetcode.com/problems/unique-paths/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/062_UniquePaths62.java) | Medium | Array / Dynamic Programming |
| [63. Unique Paths II](https://leetcode.com/problems/unique-paths-ii/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/063_UniquePathsII63.java) | Medium | Medium | Array / Dynamic Programming |
| [64. Minimum Path Sum](https://leetcode.com/problems/minimum-path-sum/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/064_MinimumPathSum64.java) | Medium | Array / Dynamic Programming |
| [65. Valid Number](https://leetcode.com/problems/valid-number/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/065_ValidNumber65.java) | Hard | Array / Dynamic Programming |
| [66. Plus One](https://leetcode.com/problems/plus-one/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/066_PlusOne66.java) | Easy | Array / Math |
| [68. Text Justification](https://leetcode.com/problems/text-justification/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/068_TextJustification68.java) | Hard | String |
| [69. Sqrt(x)](https://leetcode.com/problems/sqrtx/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/069_SqrtX69.java) | Easy | Binary Search / Math |
| [70. Climbing Stairs](https://leetcode.com/problems/climbing-stairs/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/070_ClimbingStairs70.java) | Easy | Dynamic Programming |
| [71. Simplify Path](https://leetcode.com/problems/simplify-path/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/071_SimplifyPath71.java) | Medium | Stack / String |
| [72. Edit Distance](https://leetcode.com/problems/edit-distance/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/072_EditDistance72.java) | Hard | Stack / String |
| [73. Set Matrix Zeroes](https://leetcode.com/problems/set-matrix-zeroes/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/073_SetMatrixZeroes73.java) | Medium | Array |
| [74. Search a 2D Matrix](https://leetcode.com/problems/search-a-2d-matrix/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/074_SearchA2DMatrix74.java) | Medium | Array / Binary Search |
| [75. Sort Colors](https://leetcode.com/problems/sort-colors/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/075_SortColors75.java) | Medium | Array / Two Pointers |
| [76. Minimum Window Substring](https://leetcode.com/problems/minimum-window-substring/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/076_MinimumWindowSubstring76.java) | Hard | Hash Table / Two pointers / String |
| [78. Subsets](https://leetcode.com/problems/subsets/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/078_Subsets78.java) | Medium | Array / Backtracking |
| [79. Word Search](https://leetcode.com/problems/word-search/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/079_WordSearch79.java) | Medium | Matrix / Backtracking |
| [80. Remove Duplicates from Sorted Array II](https://leetcode.com/problems/remove-duplicates-from-sorted-array-ii/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/080_RemoveDuplicatesFromSortedArrayII80.java) | Medium | Array / Two Pointers |
| [81. Search in Rotated Sorted Array II](https://leetcode.com/problems/search-in-rotated-sorted-array-ii/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/081_SearchInRotatedSortedArrayII81.java) | Medium |
| [82. Remove Duplicates from Sorted List II](https://leetcode.com/problems/remove-duplicates-from-sorted-list-ii/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/082_RemoveDuplicatesFromSortedListII82.java) | Medium | Linked List |
| [83. Remove Duplicates from Sorted List](https://leetcode.com/problems/remove-duplicates-from-sorted-list/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/083_RemoveDuplicatesFromSortedList83.java) | Easy | Linked List |
| [84. Largest Rectangle in Histogram](https://leetcode.com/problems/largest-rectangle-in-histogram/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/084_LargestRectangleInHistogram84.java) | Hard | Array |
| [85. Maximal Rectangle](https://leetcode.com/problems/maximal-rectangle/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/085_MaximalRectangle85.java) | Hard | Array |
| [86. Partition List](https://leetcode.com/problems/partition-list/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/086_PartitionList86.java) | Medium | Linked List |
| [88. Merge Sorted Array](https://leetcode.com/problems/merge-sorted-array/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/088_MergeSortedArray88.java) | Easy | Array / Two Pointers |
| [90. Subsets II](https://leetcode.com/problems/subsets-ii/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/090_SubsetsII90.java) | Medium | Array / Backtracking |
| [91. Decode Ways](https://leetcode.com/problems/decode-ways/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/091_DecodeWays91.java) | Medium | Dynamic Programming / String |
| [92. Reverse Linked List II](https://leetcode.com/problems/reverse-linked-list-ii/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/092_ReverseLinkedListII92.java) | Medium | Linked List |
| [93. Restore IP Addresses](https://leetcode.com/problems/restore-ip-addresses/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/093_RestoreIPAddresses93.java) | Medium |
| [94. Binary Tree Inorder Traversal](https://leetcode.com/problems/binary-tree-inorder-traversal/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/094_BinaryTreeInorderTraversal94.java) | Medium | Tree / Stack |
| [95. Unique Binary Search Trees II](https://leetcode.com/problems/unique-binary-search-trees-ii/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/095_UniqueBinarySearchTreesII95.java) | Medium | Tree |
| [96. Unique Binary Search Trees](https://leetcode.com/problems/unique-binary-search-trees/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/096_UniqueBinarySearchTrees96.java) | Medium | Tree / DFS |
| [97. Interleaving String](https://leetcode.com/problems/interleaving-string/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/097_InterleavingString97.java) | Hard | Tree / DFS |
| [98. Validate Binary Search Tree](https://leetcode.com/problems/validate-binary-search-tree/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/098_ValidateBinarySearchTree98.java) | Medium | Tree |
| [100. Same Tree](https://leetcode.com/problems/same-tree/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/100_SameTree100.java) | Easy | Tree / DFS | Tree / DFS |
| [101. Symmetric Tree](https://leetcode.com/problems/symmetric-tree/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/101_SymmetricTree101.java) | Easy | Tree |
| [102. Binary Tree Level Order Traversal](https://leetcode.com/problems/binary-tree-level-order-traversal/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/102_BinaryTreeLevelOrderTraversal102.java) | Medium | Tree / DFS / BFS |
| [103. Binary Tree Zigzag Level Order Traversal](https://leetcode.com/problems/binary-tree-zigzag-level-order-traversal/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/103_BinaryTreeZigzagLevelOrderTraversal103.java) | Medium | Tree / BFS |
| [104. Maximum Depth of Binary Tree](https://leetcode.com/problems/maximum-depth-of-binary-tree/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/104_MaximumDepthOfBinaryTree104.java) | Easy | Tree |
| [105. Construct Binary Tree from Preorder and Inorder Traversal](https://leetcode.com/problems/construct-binary-tree-from-preorder-and-inorder-traversal/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/105_ConstructBinaryTreeFromPreorderAndInorderTraversal105.java) | Medium | Array / Tree / DFS |
| [106. Construct Binary Tree from Inorder and Postorder Traversal](https://leetcode.com/problems/construct-binary-tree-from-inorder-and-postorder-traversal/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/106_ConstructBinaryTreeFromInorderAndPostorderTraversal106.java) | Medium |Linked List / DFS |
| [107. Binary Tree Level Order Traversal II](https://leetcode.com/problems/binary-tree-level-order-traversal-ii/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/107_BinaryTreeLevelOrderTraversalII107.java) | Easy | Tree |
| [108. Convert Sorted Array to Binary Search Tree](https://leetcode.com/problems/convert-sorted-array-to-binary-search-tree/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/108_ConvertSortedArrayToBinarySearchTree108.java) | Easy | Tree / DFS |
| [109. Convert Sorted List to Binary Search Tree](https://leetcode.com/problems/convert-sorted-list-to-binary-search-tree/) | [Solution](https://github.com/fluency03/leetcode-java/blob/master/src/ConvertSortedListToBST109.java) | Medium | Linked List / DFS |
| [110. Balanced Binary Tree](https://leetcode.com/problems/balanced-binary-tree/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/110_BalancedBinaryTree110.java) | Easy | Tree / DFS |
| [111. Minimum Depth of Binary Tree](https://leetcode.com/problems/minimum-depth-of-binary-tree/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/111_MinimumDepthOfBinaryTree111.java) | Easy | Tree |
| [112. Path Sum](https://leetcode.com/problems/path-sum/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/112_PathSum112.java) | Easy | Tree / DFS |
| [113. Path Sum II](https://leetcode.com/problems/path-sum-ii/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/113_PathSumII113.java) | Medium | Tree / DFS |
| [114. Flatten Binary Tree to Linked List](https://leetcode.com/problems/flatten-binary-tree-to-linked-list/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/114_FlattenBinaryTreeToLinkedList114.java) | Medium | Tree / DFS |
| [116. Populating Next Right Pointers in Each Node](https://leetcode.com/problems/populating-next-right-pointers-in-each-node/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/116_PopulatingNextRightPointersInEachNode116.java) | Medium | Tree / BFS |
| [117. Populating Next Right Pointers in Each Node II](https://leetcode.com/problems/populating-next-right-pointers-in-each-node-ii/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/117_PopulatingNextRightPointersInEachNodeII117.java) | Medium | Tree / Level-order Traversal |
| [119. Pascal's Triangle II](https://leetcode.com/problems/pascals-triangle-ii/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/119_PascalsTriangleII119.java) | Easy | Array |
| [120. Triangle](https://leetcode.com/problems/triangle/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/120_Triangle120.java) | Medium | Array / Dynamic Programming |
| [121. Best Time to Buy and Sell Stock](https://leetcode.com/problems/best-time-to-buy-and-sell-stock/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/121_BestTimeToBuyAndSellStock121.java) | Easy | Array / Dynamic Programming |
| [122. Best Time to Buy and Sell Stock II](https://leetcode.com/problems/best-time-to-buy-and-sell-stock-ii/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/122_BestTimeToBuyAndSellStockII122.java) | Easy | Tree / DFS |
| [123. Best Time to Buy and Sell Stock III](https://leetcode.com/problems/best-time-to-buy-and-sell-stock-iii/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/123_BestTimeToBuyAndSellStockIII123.java) | Hard | Tree / DFS |
| [124. Binary Tree Maximum Path Sum](https://leetcode.com/problems/binary-tree-maximum-path-sum/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/124_BinaryTreeMaximumPathSum124.java) | Hard | Tree / DFS |
| [125. Valid Palindrome](https://leetcode.com/problems/valid-palindrome/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/125_ValidPalindrome125.java) | Easy | String / Two Pointers |
| [126. Word Ladder II](https://leetcode.com/problems/word-ladder-ii/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/126_WordLadderII126.java) | Hard | Array / Unoin Find |
| [127. Word Ladder](https://leetcode.com/problems/word-ladder/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/127_WordLadder127.java) | Medium | String / BFS |
| [128. Longest Consecutive Sequence](https://leetcode.com/problems/longest-consecutive-sequence/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/128_LongestConsecutiveSequence128.java) | Hard | Array / Unoin Find |
| [129. Sum Root to Leaf Numbers](https://leetcode.com/problems/sum-root-to-leaf-numbers/) | [Solution](https://github.com/fluency03/leetcode-java/blob/master/src/SumRootToLeafNumbers129.java) | Medium | Tree / DFS / BFS |
| [130. Surrounded Regions](https://leetcode.com/problems/surrounded-regions/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/130_SurroundedRegions130.java) | Medium | DFS / BFS / Union Find |
| [131. Palindrome Partitioning](https://leetcode.com/problems/palindrome-partitioning/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/131_PalindromePartitioning131.java) | Medium | Backtracking |
| [133. Clone Graph](https://leetcode.com/problems/clone-graph/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/133_CloneGraph133.java) | Medium | Graph / DFS / BFS |
| [136. Single Number](https://leetcode.com/problems/single-number/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/136_SingleNumber136.java) | Easy | Bit Manipulation |
| [137. Single Number II](https://leetcode.com/problems/single-number-ii/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/137_SingleNumberII137.java) | Medium | Dynamic Programming |
| [138. Copy List with Random Pointer](https://leetcode.com/problems/copy-list-with-random-pointer/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/138_CopyListWithRandomPointer138.java) | Medium | Hash Table / Linked List |
| [139. Word Break](https://leetcode.com/problems/word-break/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/139_WordBreak139.java) | Medium | Dynamic Programming |
| [140. Word Break II](https://leetcode.com/problems/word-break-ii/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/140_WordBreakII140.java) | Hard | Dynamic Programming |
| [141. Linked List Cycle](https://leetcode.com/problems/linked-list-cycle/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/141_LinkedListCycle141.java) | Easy | Linked List / Two Pointers |
| [142. Linked List Cycle II](https://leetcode.com/problems/linked-list-cycle-ii/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/142_LinkedListCycleII142.java) | Easy | Linked List / Two Pointers |
| [143. Reorder List](https://leetcode.com/problems/reorder-list/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/143_ReorderList143.java) | Medium | Linked List |
| [144. Binary Tree Preorder Traversal](https://leetcode.com/problems/binary-tree-preorder-traversal/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/144_BinaryTreePreorderTraversal144.java) | Medium | Tree / Stack |
| [146. LRU Cache](https://leetcode.com/problems/lru-cache/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/146_LRUCache146.java) | Hard | Design |
| [147. Insertion Sort List](https://leetcode.com/problems/insertion-sort-list/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/147_InsertionSortList147.java) | Medium | Stack / Design |
| [148. Sort List](https://leetcode.com/problems/sort-list/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/148_SortList148.java) | Medium | Stack / Design |
| [149. Max Points on a Line](https://leetcode.com/problems/max-points-on-a-line/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/149_MaxPointsOnALine149.java) | Hard | Stack / Design |
| [150. Evaluate Reverse Polish Notation](https://leetcode.com/problems/evaluate-reverse-polish-notation/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/150_EvaluateReversePolishNotation150.java) | Medium |
| [151. Reverse Words in a String](https://leetcode.com/problems/reverse-words-in-a-string/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/151_ReverseWordsInAString151.java) | Medium | String |
| [152. Maximum Product Subarray](https://leetcode.com/problems/maximum-product-subarray/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/152_MaximumProductSubarray152.java) | Medium | String / Two Pointers |
| [153. Find Minimum in Rotated Sorted Array](https://leetcode.com/problems/find-minimum-in-rotated-sorted-array/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/153_FindMinimumInRotatedSortedArray153.java) | Medium | String / Two Pointers |
| [154. Find Minimum in Rotated Sorted Array II](https://leetcode.com/problems/find-minimum-in-rotated-sorted-array-ii/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/154_FindMinimumInRotatedSortedArrayII154.java) | Hard | String / Two Pointers |
| [155. Min Stack](https://leetcode.com/problems/min-stack/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/155_Min_Stack.java) | Easy | Stack / Design |
| [157. Read N Characters Given Read4](https://leetcode.com/problems/read-n-characters-given-read4/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/157_ReadNCharactersGivenReadFour157.java) | Easy | String |
| [158. Read N Characters Given Read4 II - Call multiple times](https://leetcode.com/problems/read-n-characters-given-read4-ii-call-multiple-times/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/158_ReadNCharactersGivenRead4IICallMultipleTimes158.java) | Hard | String |
| [159. Longest Substring with At Most Two Distinct Characters](https://leetcode.com/problems/longest-substring-with-at-most-two-distinct-characters/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/159_LongestSubstringWithAtMostTwoDistinctCharacters159.java) | Hard | String / Two Pointers |
| [160. Intersection of Two Linked Lists](https://leetcode.com/problems/intersection-of-two-linked-lists/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/160_IntersectionOfTwoLinkedLists160.java) | Easy | String |
| [161. One Edit Distance](https://leetcode.com/problems/one-edit-distance/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/161_OneEditDistance161.java) | Medium | String |
| [162. Find Peak Element](https://leetcode.com/problems/find-peak-element/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/162_FindPeakElement162.java) | Medium | Binary Search |
| [163. Missing Ranges](https://leetcode.com/problems/missing-ranges/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/163_MissingRanges163.java) | Medium | Array |
| [165. Compare Version Numbers](https://leetcode.com/problems/compare-version-numbers/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/165_CompareVersionNumbers165.java) | Medium |
| [166. Fraction to Recurring Decimal](https://leetcode.com/problems/fraction-to-recurring-decimal/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/166_FractionToRecurringDecimal166.java) | Medium |
| [167. Two Sum II - Input array is sorted](https://leetcode.com/problems/two-sum-ii-input-array-is-sorted/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/167_TwoSumIIInputArrayIsSorted167.java) | Easy |
| [169. Majority Element](https://leetcode.com/problems/majority-element/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/169_MajorityElement169.java) | Easy | Array |
| [173. Binary Search Tree Iterator](https://leetcode.com/problems/binary-search-tree-iterator/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/173_BinarySearchTreeIterator173.java) | Medium | Tree / Stack / Design |
| [179. Largest Number](https://leetcode.com/problems/largest-number/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/179_LargestNumber179.java) | Medium |
| [186. Reverse Words in a String II](https://leetcode.com/problems/reverse-words-in-a-string-ii/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/186_ReverseWordsInAStringII186.java) | Easy | String |
| [187. Repeated DNA Sequences](https://leetcode.com/problems/repeated-dna-sequences/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/187_RepeatedDNASequences187.java) | Medium |
| [188. Best Time to Buy and Sell Stock IV](https://leetcode.com/problems/best-time-to-buy-and-sell-stock-iv/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/188_BestTimeToBuyAndSellStockIV188.java) | Hard |
| [189. Rotate Array](https://leetcode.com/problems/rotate-array/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/189_RotateArray189.java) | Easy |
| [198. House Robber](https://leetcode.com/problems/house-robber/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/198_HouseRobber198.java) | Easy | Dynamic Programming |
| [199. Binary Tree Right Side View](https://leetcode.com/problems/binary-tree-right-side-view/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/199_BinaryTreeRightSideView199.java) | Medium |
| [200. Number of Islands](https://leetcode.com/problems/number-of-islands/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/200_NumberOfIslands200.java) | Medium | BFS / Union Find |
| [201. Bitwise AND of Numbers Range](https://leetcode.com/problems/bitwise-and-of-numbers-range/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/201_BitwiseANDOfNumbersRange201.java) | Medium |
| [202. Happy Number](https://leetcode.com/problems/happy-number/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/202_HappyNumber202.java) | Easy |
| [203. Remove Linked List Elements](https://leetcode.com/problems/remove-linked-list-elements/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/203_RemoveLinkedListElements203.java) | Easy |
| [204. Count Primes](https://leetcode.com/problems/count-primes/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/204_Count_Primes.java) | Easy |
| [205. Isomorphic Strings](https://leetcode.com/problems/isomorphic-strings/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/205_IsomorphicStrings205.java) | Easy | Hash Table |
| [206. Reverse Linked List](https://leetcode.com/problems/reverse-linked-list/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/206_ReverseLinkedList206.java) | Easy | Linked List |
| [207. Course Schedule](https://leetcode.com/problems/course-schedule/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/207_CourseSchedule207.java) | Medium | Graph / BFS / Topological Sort |
| [208. Implement Trie (Prefix Tree)](https://leetcode.com/problems/implement-trie-prefix-tree/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/208_ImplementTriePrefixTree208.java) | Medium | Trie / Design |
| [209. Minimum Size Subarray Sum](https://leetcode.com/problems/minimum-size-subarray-sum/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/209_MinimumSizeSubarraySum209.java) | Medium | Array / Two Pointers |
| [210. Course Schedule II](https://leetcode.com/problems/course-schedule-ii/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/210_CourseScheduleII210.java) | Medium | Graph / BFS / Topological Sort |
| [212. Word Search II](https://leetcode.com/problems/word-search-ii/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/212_WordSearchII212.java) | Hard |
| [213. House Robber II](https://leetcode.com/problems/house-robber-ii/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/213_HouseRobberII213.java) | Medium |
| [214. Shortest Palindrome](https://leetcode.com/problems/shortest-palindrome/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/214_ShortestPalindrome214.java) | Medium | String |
| [215. Kth Largest Element in an Array](https://leetcode.com/problems/kth-largest-element-in-an-array/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/215_Kth_Largest_Element_in_an_Array.java) | Medium | Medium | Sort / Partition |
| [216. Combination Sum III](https://leetcode.com/problems/combination-sum-iii/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/216_CombinationSumIII216.java) | Medium |
| [217. Contains Duplicate](https://leetcode.com/problems/contains-duplicate/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/217_ContainsDuplicate217.java) | Easy |
| [218. The Skyline Problem](https://leetcode.com/problems/the-skyline-problem/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/218_TheSkylineProblem218.java) | Hard |
| [219. Contains Duplicate II](https://leetcode.com/problems/contains-duplicate-ii/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/219_ContainsDuplicatesII219.java) | Easy |
| [220. Contains Duplicate III](https://leetcode.com/problems/contains-duplicate-iii/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/220_ContainsDuplicateIII220.java) | Medium |
| [221. Maximal Square](https://leetcode.com/problems/maximal-square/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/221_MaximalSquare221.java) | Medium | Dynamic Programming / BFS |
| [223. Rectangle Area](https://leetcode.com/problems/rectangle-area/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/223_Rectangle_Area.java) | Medium | Math |
| [224. Basic Calculator](https://leetcode.com/problems/basic-calculator/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/224_BasicCalculator224.java) | Hard | String / Stack |
| [226. Invert Binary Tree](https://leetcode.com/problems/invert-binary-tree/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/226_InvertBinaryTree226.java) | Easy | Tree |
| [227. Basic Calculator II](https://leetcode.com/problems/basic-calculator-ii/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/227_BasicCalculatorII227.java) | Medium | String |
| [230. Kth Smallest Element in a BST](https://leetcode.com/problems/kth-smallest-element-in-a-bst/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/230_KthSmallestElementInABST230.java) | Medium | Tree |
| [231. Power of Two](https://leetcode.com/problems/power-of-two/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/231_PowerOfTwo231.java) | Easy | Easy |
| [232. Implement Queue using Stacks](https://leetcode.com/problems/implement-queue-using-stacks/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/232_ImplementQueueUsingStacks232.java) | Easy |
| [233. Number of Digit One](https://leetcode.com/problems/number-of-digit-one/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/233_NumberOfDigitOne233.java) | Hard |
| [234. Palindrome Linked List](https://leetcode.com/problems/palindrome-linked-list/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/234_PalindromeLinkedList234.java) | Easy | Linked List / Two Pointers |
| [235. Lowest Common Ancestor of a Binary Search Tree](https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-search-tree/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/235_LowestCommonAncestorOfABinarySearchTree235.java) | Easy | Tree |
| [236. Lowest Common Ancestor of a Binary Tree](https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-tree/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/236_Lowest_Common_Ancestor_of_a_Binary_Tree.java) | Medium | Tree |
| [237. Delete Node in a Linked List](https://leetcode.com/problems/delete-node-in-a-linked-list/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/237_DeleteNodeInALinkedList237.java) | Easy |
| [238. Product of Array Except Self](https://leetcode.com/problems/product-of-array-except-self/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/238_Product_of_Array_Except_Self.java) | Medium |Array |
| [239. Sliding Window Maximum](https://leetcode.com/problems/sliding-window-maximum/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/239_SlidingWindowMaximum239.java) | Hard |Heap |
| [240. Search a 2D Matrix II](https://leetcode.com/problems/search-a-2d-matrix-ii/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/240_SearchA2DMatrixII240.java) | Medium | Binary Search / Divide and Conquer |
| [241. Different Ways to Add Parentheses](https://leetcode.com/problems/different-ways-to-add-parentheses/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/241_DifferentWaysToAddParentheses241.java) | Medium |
| [242. Valid Anagram](https://leetcode.com/problems/valid-anagram/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/242_ValidAnagram242.java) | Easy |
| [243. Shortest Word Distance](https://leetcode.com/problems/shortest-word-distance/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/243_ShortestWordDistance243.java) | Easy |
| [246. Strobogrammatic Number](https://leetcode.com/problems/strobogrammatic-number/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/246_StrobogrammaticNumber246.java) | Easy | Hash Table / Math |
| [247. Strobogrammatic Number II](https://leetcode.com/problems/strobogrammatic-number-ii/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/247_StrobogrammaticNumberII247.java) | Medium | Math / Recursion |
| [249. Group Shifted Strings](https://leetcode.com/problems/group-shifted-strings/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/249_GroupShiftedStrings249.java) | Medium | String |
| [251. Flatten 2D Vector](https://leetcode.com/problems/flatten-2d-vector/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/251_Flatten2DVector251.java) | Medium | Design |
| [252. Meeting Rooms](https://leetcode.com/problems/meeting-rooms/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/252_MeetingRooms252.java) | Easy | Sort |
| [253. Meeting Rooms II](https://leetcode.com/problems/meeting-rooms-ii/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/253_MeetingRoomsII253.java) | Medium | Heap / Sort |
| [255. Verify Preorder Sequence in Binary Search Tree](https://leetcode.com/problems/verify-preorder-sequence-in-binary-search-tree/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/255_ImplementStackusingQueues225.java) | Medium | Medium | Stack / Tree |
| [256. Paint House](https://leetcode.com/problems/paint-house/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/256_PaintHouse256.java) | Easy |
| [257. Binary Tree Paths](https://leetcode.com/problems/binary-tree-paths/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/257_BinaryTreePaths257.java) | Easy | Tree / DFS / BFS |
| [259. 3Sum Smaller](https://leetcode.com/problems/3sum-smaller/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/259_ThreeSumSmaller259.java) | Medium | Array / Two Pointers |
| [261. Graph Valid Tree](https://leetcode.com/problems/graph-valid-tree/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/261_GraphValidTree261.java) | Medium | Graph / BFS / DFS / Union Find |
| [263. Ugly Number](https://leetcode.com/problems/ugly-number/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/263_UglyNumber263.java) | Easy | Math |
| [264. Ugly Number II](https://leetcode.com/problems/ugly-number-ii/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/264_UglyNumberII264.java) | Medium | Dynamic Programming / Math |
| [265. Paint House II](https://leetcode.com/problems/paint-house-ii/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/265_PaintHouseII265.java) | Hard |
| [267. Palindrome Permutation II](https://leetcode.com/problems/palindrome-permutation-ii/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/267_PalindromePermutationII267.java) | Medium |Backtracking | [discuss](https://leetcode.com/problems/palindrome-permutation-ii/discuss/121889/3ms-C++-backtracking) |
| [268. Missing Number](https://leetcode.com/problems/missing-number/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/268_Missing_Number.java) | Easy | Array / Bit Manipulation | [discuss](https://leetcode.com/problems/missing-number/discuss/131408/3-lines-C++) |
| [269. Alien Dictionary](https://leetcode.com/problems/alien-dictionary/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/269_AlienDictionary269.java) | Hard | Graph / Topological Sort | [discuss](https://discuss.leetcode.com/topic/107067/short-c-bfs-topological-sort) |
| [270. Closest Binary Search Tree Value](https://leetcode.com/problems/closest-binary-search-tree-value/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/270_ClosestBinarySearchTreeValue270.java) | Easy |Tree / Binary Search | [discuss](https://discuss.leetcode.com/topic/108393/7-lines-c) |
| [271. Encode and Decode Strings](https://leetcode.com/problems/encode-and-decode-strings/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/271_EncodeAndDecodeStrings271.java) | Medium | String / Design | [discuss](https://discuss.leetcode.com/topic/104401/c-encode-with) |
| [272. Closest Binary Search Tree Value II](https://leetcode.com/problems/closest-binary-search-tree-value-ii/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/272_ClosestBinarySearchTreeValueII272.java) | Medium | Tree / Stack |
| [273. Integer to English Words](https://leetcode.com/problems/integer-to-english-words/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/273_Integer_to_English_Words.java) | Hard | String | [discuss](https://discuss.leetcode.com/topic/104627/3ms-short-c) |
| [274. H-Index](https://leetcode.com/problems/h-index/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/274_HIndex274.java) | Medium | Sort | [discuss](https://discuss.leetcode.com/topic/101496/4-lines-c) |
| [276. Paint Fence](https://leetcode.com/problems/paint-fence/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/276_PaintFence276.java) | Easy | Dynamic Programming | [discuss](https://discuss.leetcode.com/topic/91156/4-lines-c) |
| [277. Find the Celebrity](https://leetcode.com/problems/find-the-celebrity/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/277_FindTheCelebrity277.java) | Medium | Array | [discuss](https://discuss.leetcode.com/topic/99937/c-o-n) |
| [278. First Bad Version](https://leetcode.com/problems/first-bad-version/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/278_FirstBadVersion278.java) | Easy | Binary Search |
| [279. Perfect Squares](https://leetcode.com/problems/perfect-squares/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/279_PerfectSquares279.java) | Medium | Math / Dynamic Programming | [discuss](https://discuss.leetcode.com/topic/108483/c-6ms-static-dp) |
| [280. Wiggle Sort](https://leetcode.com/problems/wiggle-sort/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/280_WiggleSort280.java) | Medium | Array | [discuss](https://discuss.leetcode.com/topic/97352/short-c) |
| [281. Zigzag Iterator](https://leetcode.com/problems/zigzag-iterator/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/281_ZigzagIterator281.java) | Medium |Design | [discuss](https://discuss.leetcode.com/topic/104332/c-o-1-space-and-follow-up-for-k-vectors) |
| [282. Expression Add Operators](https://leetcode.com/problems/expression-add-operators/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/282_ExpressionAddOperators282.java) | Hard | Divide and Conquer | [discuss](https://discuss.leetcode.com/topic/99983/c-backtracking) |
| [283. Move Zeroes](https://leetcode.com/problems/move-zeroes/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/283_MoveZeroes283.java) | Easy | Array / Two Pointers | [discuss](https://discuss.leetcode.com/topic/85925/c-3-lines-solution) |
| [284. Peeking Iterator](https://leetcode.com/problems/peeking-iterator/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/284_PeekingIterator284.java) | Medium | Design | [discuss](https://discuss.leetcode.com/topic/105798/c-using-deque) |
| [285. Inorder Successor in BST](https://leetcode.com/problems/inorder-successor-in-bst/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/285_InorderSuccessorInBST285.java) | Medium | Tree | [discuss](https://discuss.leetcode.com/topic/100023/c-solution-for-any-binary-tree) |
| [286. Walls and Gates](https://leetcode.com/problems/walls-and-gates/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/286_WallsAndGates286.java) | Medium | BFS | [discuss](https://discuss.leetcode.com/topic/100331/c-bfs-from-inf-or-0) |
| [287. Find the Duplicate Number](https://leetcode.com/problems/find-the-duplicate-number/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/287_FindTheDuplicateNumber287.java) | Medium |
| [288. Unique Word Abbreviation](https://leetcode.com/problems/unique-word-abbreviation/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/288_UniqueWordAbbreviation288.java) | Medium |
| [289. Game of Life](https://leetcode.com/problems/game-of-life/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/289_GameOfLife289.java) | Medium | Array | [discuss](https://discuss.leetcode.com/topic/95672/c-in-place-solution) |
| [290. Word Pattern](https://leetcode.com/problems/word-pattern/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/290_WordPattern290.java) | Easy | Hash Table | [discuss](https://discuss.leetcode.com/topic/107956/11-lines-c) |
| [291. Word Pattern II](https://leetcode.com/problems/word-pattern-ii/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/291_WordPatternII291.java) | Hard |
| [293. Flip Game](https://leetcode.com/problems/flip-game/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/293_FlipGame293.java) | Easy | String | [discuss](https://discuss.leetcode.com/topic/108535/8-lines-c) |
| [295. Find Median from Data Stream](https://leetcode.com/problems/find-median-from-data-stream/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/295_FindMedianFromDataStream295.java) | Hard | Heap / Design | [discuss](https://discuss.leetcode.com/topic/107631/c-two-heaps) |
| [296. Best Meeting Point](https://leetcode.com/problems/best-meeting-point/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/296_BestMeetingPoint296.java) | Hard |
| [297. Serialize and Deserialize Binary Tree](https://leetcode.com/problems/serialize-and-deserialize-binary-tree/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/297_SerializeAndDeserializeBinaryTree297.java) | Hard | Tree / Design |
| [298. Binary Tree Longest Consecutive Sequence](https://leetcode.com/problems/binary-tree-longest-consecutive-sequence/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/298_BinaryTreeLongestConsecutiveSequence298.java) | Medium | Tree |
| [299. Bulls and Cows](https://leetcode.com/problems/bulls-and-cows/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/299_BullsAndCows299.java) | Medium |
| [300. Longest Increasing Subsequence](https://leetcode.com/problems/longest-increasing-subsequence/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/300_LongestIncreasingSubsequence300.java) | Medium |Binary Search / Dynamic Programming | [discuss](https://discuss.leetcode.com/topic/106903/short-c-o-n-2-dp-and-o-nlogn-binary-search) |
| [301. Remove Invalid Parentheses](https://leetcode.com/problems/remove-invalid-parentheses/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/301_RemoveInvalidParentheses301.java) | Hard |Backtracking / DFS / BFS | [discuss](https://discuss.leetcode.com/topic/99881/c-backtrack-easy-to-understand) |
| [303. Range Sum Query - Immutable](https://leetcode.com/problems/range-sum-query-immutable/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/303_RangeSumQueryImmutable303.java) | Easy |Dynamic Programming | [discuss](https://discuss.leetcode.com/topic/104447/7-lines-c-dp) |
| [304. Range Sum Query 2D - Immutable](https://leetcode.com/problems/range-sum-query-2d-immutable/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/304_RangeSumQuery2DImmutable304.java) | Medium | Dynamic Programming | [discuss](https://discuss.leetcode.com/topic/104453/7-lines-c-dp) |
| [305. Number of Islands II](https://leetcode.com/problems/number-of-islands-ii/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/305_NumberOfIslandsII305.java) | Hard | Union Find | [discuss](https://discuss.leetcode.com/topic/107415/clean-c-union-find) |
| [307. Range Sum Query - Mutable](https://leetcode.com/problems/range-sum-query-mutable/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/307_RangeSumQueryMutable307.java) | Medium |Segment Tree | [discuss](https://discuss.leetcode.com/topic/104511/c-749ms-brute-force) |
| [308. Range Sum Query 2D - Mutable](https://leetcode.com/problems/range-sum-query-2d-mutable/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/308_RangeSumQuery2DMutable308.java) | Hard |
| [309. Best Time to Buy and Sell Stock with Cooldown](https://leetcode.com/problems/best-time-to-buy-and-sell-stock-with-cooldown/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/309_BestTimeToBuyAndSellStockWithCooldown309.java) | Medium | Dynamic Programming | [discuss](https://discuss.leetcode.com/topic/108594/share-my-6ms-c-dp-solution) |
| [310. Minimum Height Trees](https://leetcode.com/problems/minimum-height-trees/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/310_MinimumHeightTrees310.java) | Medium | BFS/ Graph | [discuss](https://discuss.leetcode.com/topic/100685/c-from-bf-1880ms-to-o-n-35ms-beats-99-with-explanation) |
| [311. Sparse Matrix Multiplication](https://leetcode.com/problems/sparse-matrix-multiplication/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/311_SparseMatrixMultiplication311.java) | Medium | Matrix | [discuss](https://discuss.leetcode.com/topic/98234/clean-10-lines-c) |
| [312. Burst Balloons](https://leetcode.com/problems/burst-balloons/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/312_BurstBalloons312.java) | Hard |
| [313. Super Ugly Number](https://leetcode.com/problems/super-ugly-number/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/313_SuperUglyNumber313.java) | Medium | Dynamic Programming / Math | [discuss](https://discuss.leetcode.com/topic/102178/clean-9-lines-c) |
| [314. Binary Tree Vertical Order Traversal](https://leetcode.com/problems/binary-tree-vertical-order-traversal/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/314_BinaryTreeVerticalOrderTraversal314.java) | Medium | BFS | [discuss](https://discuss.leetcode.com/topic/99884/clean-3-ms-bfs-c) |
| [315. Count of Smaller Numbers After Self](https://leetcode.com/problems/count-of-smaller-numbers-after-self/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/315_CountOfSmallerNumbersAfterSelf315.java) | Hard | Divide and Conqur / Binary Search Tree | [discuss](https://discuss.leetcode.com/topic/107641/c-bst) |
| [317. Shortest Distance from All Buildings](https://leetcode.com/problems/shortest-distance-from-all-buildings/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/317_ShortestDistanceFromAllBuildings317.java) | Hard | BFS | [discuss](https://discuss.leetcode.com/topic/107548/clean-c-bfs) |
| [318. Maximum Product of Word Lengths](https://leetcode.com/problems/maximum-product-of-word-lengths/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/318_MaximumProductOfWordLengths318.java) | Medium | Bit Manipulation | [discuss](https://discuss.leetcode.com/topic/97533/two-clean-solutions-c) |
| [320. Generalized Abbreviation](https://leetcode.com/problems/generalized-abbreviation/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/320_GeneralizedAbbreviation320.java) | Medium |
| [322. Coin Change](https://leetcode.com/problems/coin-change/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/322_CoinChange322.java) | Medium |
| [323. Number of Connected Components in an Undirected Graph](https://leetcode.com/problems/number-of-connected-components-in-an-undirected-graph/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/323_NumberOfConnectedComponentsInAnUndirectedGraph323.java) | Medium | Graph / Union Find / BFS / DFS | [discuss](https://discuss.leetcode.com/topic/105915/c-dfs-and-bfs-solution) |
| [324. Wiggle Sort II](https://leetcode.com/problems/wiggle-sort-ii/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/324_WiggleSortII324.java) | Medium |
| [325. Maximum Size Subarray Sum Equals k](https://leetcode.com/problems/maximum-size-subarray-sum-equals-k/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/325_MaximumSizeSubarraySumEqualsK325.java) | Medium | Array / Hash Table | [discuss](https://discuss.leetcode.com/topic/99871/10-lines-c-o-n) |
| [327. Count of Range Sum](https://leetcode.com/problems/count-of-range-sum/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/327_CountOfRangeSum327.java) | Hard |
| [328. Odd Even Linked List](https://leetcode.com/problems/odd-even-linked-list/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/328_OddEvenLinkedList328.java) | Medium |
| [332. Reconstruct Itinerary](https://leetcode.com/problems/reconstruct-itinerary/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/332_ReconstructItinerary332.java) | Medium | Graph / DFS | [discuss](https://discuss.leetcode.com/topic/107397/c-min-heap) |
| [333. Largest BST Subtree](https://leetcode.com/problems/largest-bst-subtree/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/333_LargestBSTSubtree333.java) | Medium | Tree | [discuss](https://leetcode.com/problems/largest-bst-subtree/discuss/116233/9-lines-12ms-C++-O(n)-solution) |
| [334. Increasing Triplet Subsequence](https://leetcode.com/problems/increasing-triplet-subsequence/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/334_IncreasingTripletSubsequence334.java) | Medium |Array | [discuss](https://discuss.leetcode.com/topic/97462/straight-forward-c-o-n-time-o-1-space-with-comments) |
| [336. Palindrome Pairs](https://leetcode.com/problems/palindrome-pairs/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/336_Palindrome_Pairs.java) | Hard | Hash Table / String / Trie | [discuss](https://discuss.leetcode.com/topic/107615/short-c-trie) |
| [337. House Robber III](https://leetcode.com/problems/house-robber-iii/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/337_HouseRobberIII337.java) | Medium |
| [338. Counting Bits](https://leetcode.com/problems/counting-bits/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/338_CountingBits338.java) | Medium |
| [339. Nested List Weight Sum](https://leetcode.com/problems/nested-list-weight-sum/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/339_NestedListWeightSum339.java) | Easy | DFS | [discuss](https://leetcode.com/problems/nested-list-weight-sum/discuss/121963/Simple-5-lines-C++) |
| [340. Longest Substring with At Most K Distinct Characters](https://leetcode.com/problems/longest-substring-with-at-most-k-distinct-characters/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/340_LongestSubstringWithAtMostKDistinctCharacters340.java) | Hard | Hash Table / String | [discuss](https://discuss.leetcode.com/topic/104376/easy-8-lines-c-o-n) |
| [343. Integer Break](https://leetcode.com/problems/integer-break/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/343_IntegerBreak343.java) | Medium |
| [344. Reverse String](https://leetcode.com/problems/reverse-string/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/344_ReverseString344.java) | Easy | String | [discuss](https://discuss.leetcode.com/topic/77597/simple-c-9ms-solution) |
| [345. Reverse Vowels of a String](https://leetcode.com/problems/reverse-vowels-of-a-string/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/345_ReverseVowelsOfAString345.java) | Easy |
| [346. Moving Average from Data Stream](https://leetcode.com/problems/moving-average-from-data-stream/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/346_MovingAverageFromDataStream346.java) | Easy |
| [347. Top K Frequent Elements](https://leetcode.com/problems/top-k-frequent-elements/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/347_TopKFrequentElements347.java) | Medium | Hash Table / Heap | [discuss](https://discuss.leetcode.com/topic/95435/7-lines-c-o-nlogn-solutions-maxheap-minheap) |
| [348. Design Tic-Tac-Toe](https://leetcode.com/problems/design-tic-tac-toe/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/348_DesignTicTacToe348.java) | Medium | Design | [discuss](https://discuss.leetcode.com/topic/106788/26ms-c-easy-to-understand) |
| [349. Intersection of Two Arrays](https://leetcode.com/problems/intersection-of-two-arrays/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/349_IntersectionOfTwoArrays349.java) | Easy |
| [350. Intersection of Two Arrays II](https://leetcode.com/problems/intersection-of-two-arrays-ii/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/350_IntersectionOfTwoArraysII350.java) | Easy |
| [351. Android Unlock Patterns](https://leetcode.com/problems/android-unlock-patterns/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/351_AndroidUnlockPatterns351.java) | Medium | DFS / Dynamic Programming | [discuss](https://leetcode.com/problems/android-unlock-patterns/discuss/198845/C++-dfs-easy-to-understand) |
| [352. Data Stream as Disjoint Intervals](https://leetcode.com/problems/data-stream-as-disjoint-intervals/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/352_DataStreamAsDisjointIntervals352.java) | Hard |
| [353. Design Snake Game](https://leetcode.com/problems/design-snake-game/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/353_DesignSnakeGame353.java) | Medium |
| [354. Russian Doll Envelopes](https://leetcode.com/problems/russian-doll-envelopes/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/354_RussianDollEnvelopes354.java) | Hard | Binary Search / Dynamic Programming | [discuss](https://leetcode.com/problems/russian-doll-envelopes/discuss/134395/10-lines-C++) |
| [355. Design Twitter](https://leetcode.com/problems/design-twitter/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/355_DesignTwitter355.java) | Medium | Hash Table / Design | [discuss](https://discuss.leetcode.com/topic/82459/simple-11-lines-c-o-n-solution) |
| [357. Count Numbers with Unique Digits](https://leetcode.com/problems/count-numbers-with-unique-digits/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/357_CountNumbersWithUniqueDigits357.java) | Medium |
| [358. Rearrange String k Distance Apart](https://leetcode.com/problems/rearrange-string-k-distance-apart/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/358_RearrangeStringKDistanceApart358.java) | Hard |
| [359. Logger Rate Limiter](https://leetcode.com/problems/logger-rate-limiter/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/359_LoggerRateLimiter359.java) | Easy | Hash Table / Design ||
| [360. Sort Transformed Array](https://leetcode.com/problems/sort-transformed-array/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/360_SortTransformedArray360.java) | Medium | Math / Two Pointers | [discuss](https://discuss.leetcode.com/topic/107606/short-c-o-n-easy-to-understand) |
| [361. Bomb Enemy](https://leetcode.com/problems/bomb-enemy/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/361_BombEnemy361.java) | Medium | Dynamic Programming | [discuss](https://discuss.leetcode.com/topic/104340/clean-c-direction-based-solution) |
| [362. Design Hit Counter](https://leetcode.com/problems/design-hit-counter/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/362_DesignHitCounter362.java) | Medium | Design | [discuss](https://discuss.leetcode.com/topic/105787/4-lines-c) |
| [363. Max Sum of Rectangle No Larger Than K](https://leetcode.com/problems/max-sum-of-rectangle-no-larger-than-k/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/363_MaxSumOfRectangleNoLargerThanK363.java) | Hard |
| [365. Water and Jug Problem](https://leetcode.com/problems/water-and-jug-problem/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/365_WaterAndJugProblem365.java) | Medium |
| [368. Largest Divisible Subset](https://leetcode.com/problems/largest-divisible-subset/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/368_LargestDivisibleSubset368.java) | Medium |
| [369. Plus One Linked List](https://leetcode.com/problems/plus-one-linked-list/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/369_PlusOneLinkedList369.java) | Medium | Linked List | [discuss](https://discuss.leetcode.com/topic/105864/simple-c-reverse-list-and-add) |
| [370. Range Addition](https://leetcode.com/problems/range-addition/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/370_RangeAddition370.java) | Medium |
| [373. Find K Pairs with Smallest Sums](https://leetcode.com/problems/find-k-pairs-with-smallest-sums/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/373_FindKPairsWithSmallestSums373.java) | Medium | Heap | [discuss](https://discuss.leetcode.com/topic/106033/7-lines-c-minheap-and-maxheap) |
| [375. Guess Number Higher or Lower II](https://leetcode.com/problems/guess-number-higher-or-lower-ii/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/375_GuessNumberHigherOrLowerII375.java) | Medium |
| [377. Combination Sum IV](https://leetcode.com/problems/combination-sum-iv/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/377_CombinationSumIV377.java) | Medium | Dynamic Programming | [discuss](https://discuss.leetcode.com/topic/100273/c-recursion) |
| [378. Kth Smallest Element in a Sorted Matrix](https://leetcode.com/problems/kth-smallest-element-in-a-sorted-matrix/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/378_KthSmallestElementInASortedMatrix378.java) | Medium | Binary Search / Heap |
| [380. Insert Delete GetRandom O(1)](https://leetcode.com/problems/insert-delete-getrandom-o1/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/380_InsertDeleteGetRandomOOne380.java) | Medium | Hash Table / Design | [discuss](https://discuss.leetcode.com/topic/104313/10-lines-c-92ms) |
| [382. Linked List Random Node](https://leetcode.com/problems/linked-list-random-node/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/382_LinkedListRandomNode382.java) | Medium |Reservoir Sampling | [discuss](https://discuss.leetcode.com/topic/106031/c-reservoir-sampling) |
| [383. Ransom Note](https://leetcode.com/problems/ransom-note/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/383_Ransom_Note.java) | Easy |
| [384. Shuffle an Array](https://leetcode.com/problems/shuffle-an-array/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/384_ShuffleAnArray384.java) | Medium |
| [386. Lexicographical Numbers](https://leetcode.com/problems/lexicographical-numbers/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/386_LexicographicalNumbers386.java) | Medium |
| [387. First Unique Character in a String](https://leetcode.com/problems/first-unique-character-in-a-string/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/387_FirstUniqueCharacterInAString387.java) | Easy |
| [392. Is Subsequence](https://leetcode.com/problems/is-subsequence/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/392_IsSubsequence392.java) | Medium |
| [393. UTF-8 Validation](https://leetcode.com/problems/utf-8-validation/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/393_UTF8Validation393.java) | Medium |
| [394. Decode String](https://leetcode.com/problems/decode-string/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/394_DecodeString394.java) | Medium | String / DFS | [discuss](https://discuss.leetcode.com/topic/104396/c-0ms-recursion) |
| [396. Rotate Function](https://leetcode.com/problems/rotate-function/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/396_RotateFunction396.java) | Medium |
| [399. Evaluate Division](https://leetcode.com/problems/evaluate-division/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/399_EvaluateDivision399.java) | Medium | Graph | [discuss](https://discuss.leetcode.com/topic/105762/clean-3ms-c-bfs) |
| [403. Frog Jump](https://leetcode.com/problems/frog-jump/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/403_FrogJump403.java) | Hard |
| [405. Convert a Number to Hexadecimal](https://leetcode.com/problems/convert-a-number-to-hexadecimal/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/405_Convert_a_Number_to_Hexadecimal.java) | Easy |
| [406. Queue Reconstruction by Height](https://leetcode.com/problems/queue-reconstruction-by-height/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/406_QueueReconstructionByHeight406.java) | Medium |
| [407. Trapping Rain Water II](https://leetcode.com/problems/trapping-rain-water-ii/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/407_TrappingRainWaterII407.java) | Medium |
| [408. Valid Word Abbreviation](https://leetcode.com/problems/valid-word-abbreviation/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/408_ValidWordAbbreviation408.java) | Easy |String | [discuss](https://discuss.leetcode.com/topic/108894/short-c-solution) |
| [409. Longest Palindrome](https://leetcode.com/problems/longest-palindrome/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/409_Longest_Palindrome.java) | Easy | Hash Table | [discuss](https://discuss.leetcode.com/topic/109840/4-lines-c) |
| [410. Split Array Largest Sum](https://leetcode.com/problems/split-array-largest-sum/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/410_SplitArrayLargestSum410.java) | Hard |
| [412. Fizz Buzz](https://leetcode.com/problems/fizz-buzz/description/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/412_FizzBuzz412.java) | Easy | Array | [discuss](https://discuss.leetcode.com/topic/85930/c-3ms) |
| [416. Partition Equal Subset Sum](https://leetcode.com/problems/partition-equal-subset-sum/description/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/416_PartitionEqualSubsetSum416.java) | Medium | Dynamic Programming | [discuss](https://discuss.leetcode.com/topic/108717/9-lines-c-dp) |
| [417. Pacific Atlantic Water Flow](https://leetcode.com/problems/pacific-atlantic-water-flow/description/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/417_PacificAtlanticWaterFlow417.java) | Medium | DFS / BFS | [discuss](https://discuss.leetcode.com/topic/105705/c-dfs-easy-to-understand) |
| [418. Sentence Screen Fitting](https://leetcode.com/problems/sentence-screen-fitting/description/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Java/blob/master/418_SentenceScreenFitting418.java) | Medium | Dynamic Programming ||
| [433. Minimum Genetic Mutation](https://leetcode.com/problems/minimum-genetic-mutation/description/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/433.%20Minimum%20Genetic%20Mutation.cpp) | Medium | BFS | [discuss](https://discuss.leetcode.com/topic/101984/clean-c-bfs-same-as-word-ladder) |
| [435. Non-overlapping Intervals](https://leetcode.com/problems/non-overlapping-intervals/description/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/435.%20Non-overlapping%20Intervals.cpp) | Medium | Greedy | [discuss](https://leetcode.com/problems/non-overlapping-intervals/discuss/116085/11-lines-C++) |
| [436. Find Right Interval](https://leetcode.com/problems/find-right-interval/description/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/436.%20Find%20Right%20Interval.cpp) | Medium | Array / Binary Search | [discuss](https://leetcode.com/problems/find-right-interval/discuss/116073/8-lines-C++) |
| [438. Find All Anagrams in a String](https://leetcode.com/problems/find-all-anagrams-in-a-string/description/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/438.%20Find%20All%20Anagrams%20in%20a%20String.cpp) | Easy | Hash Table | [discuss](https://discuss.leetcode.com/topic/111121/12-lines-c-o-n-solution) |
| [441. Arranging Coins](https://leetcode.com/problems/arranging-coins/description/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/441.%20Arranging%20Coins.cpp) | Easy | Math | [discuss](https://discuss.leetcode.com/topic/92001/3-lines-c-easy-to-understand) |
| [444. Sequence Reconstruction](https://leetcode.com/problems/sequence-reconstruction/description/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/444.%20Sequence%20Reconstruction.cpp) | Medium | Graph / Topological Sort | [discuss](https://discuss.leetcode.com/topic/108886/short-c-topological-sort-solution-easy-to-understand) |
| [450. Delete Node in a BST](https://leetcode.com/problems/delete-node-in-a-bst/description/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/450.%20Delete%20Node%20in%20a%20BST.cpp) | Medium | Tree | [discuss](https://leetcode.com/problems/delete-node-in-a-bst/discuss/137641/10-lines-C++) |
| [451. Sort Characters By Frequency](https://leetcode.com/problems/sort-characters-by-frequency/description/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/451.%20Sort%20Characters%20By%20Frequency.cpp) | Medium | Hash Table / Heap | [discuss](https://discuss.leetcode.com/topic/106967/c-o-nlogn-hash-table-priority_queue) |
| [461. Hamming Distance](https://leetcode.com/problems/hamming-distance/description/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/461.%20Hamming%20Distance.cpp) | Easy | Bit Manipulation | [discuss](https://discuss.leetcode.com/topic/85931/4-lines-c-3ms) |
| [467. Unique Substrings in Wraparound String](https://leetcode.com/problems/unique-substrings-in-wraparound-string/description/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/467.%20Unique%20Substrings%20in%20Wraparound%20String.cpp) | Medium | Dynamic Programming | [discuss](https://discuss.leetcode.com/topic/104587/9-lines-c) |
| [473. Matchsticks to Square](https://leetcode.com/problems/matchsticks-to-square/description/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/473.%20Matchsticks%20to%20Square.cpp) | Medium | DFS | [discuss](https://discuss.leetcode.com/topic/119716/c-17ms-dfs-solution) |
| [477. Total Hamming Distance](https://leetcode.com/problems/total-hamming-distance/description/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/477.%20Total%20Hamming%20Distance.cpp) | Medium | Bit Manipulation | [discuss](https://discuss.leetcode.com/topic/100420/7-lines-c-o-n) |
| [482. License Key Formatting](https://leetcode.com/problems/license-key-formatting/description/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/482.%20License%20Key%20Formatting.cpp) | Medium | Array | [discuss](https://discuss.leetcode.com/topic/104317/9ms-straight-forward-c) |
| [484. Find Permutation](https://leetcode.com/problems/find-permutation/description/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/484.%20Find%20Permutation.cpp) | Medium | Greedy | [discuss](https://discuss.leetcode.com/topic/105887/9-lines-c) |
| [486. Predict the Winner](https://leetcode.com/problems/predict-the-winner/description/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/486.%20Predict%20the%20Winner.cpp) | Medium | Dynamic Programming / Minimax | [discuss](https://leetcode.com/problems/predict-the-winner/discuss/197984/C++-0ms-minimax) |
| [487. Max Consecutive Ones II](https://leetcode.com/problems/max-consecutive-ones-ii/description/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/487.%20Max%20Consecutive%20Ones%20II.cpp) | Medium | Two Pointers | [discuss](https://leetcode.com/problems/max-consecutive-ones-ii/discuss/122406/7-lines-C++-two-pointers) |
| [489. Robot Room Cleaner](https://leetcode.com/problems/robot-room-cleaner/description/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/489.%20Robot%20Room%20Cleaner.cpp) | Hard | DFS | [discuss](https://leetcode.com/problems/robot-room-cleaner/discuss/199348/C++-dfs-easy-to-understand) |
| [490. The Maze](https://leetcode.com/problems/the-maze/description/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/490.%20The%20Maze.cpp) | Medium | BFS / DFS | |
| [494. Target Sum](https://leetcode.com/problems/target-sum/description/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/494.%20Target%20Sum.cpp) | Medium | Backtracking | [discuss](https://discuss.leetcode.com/topic/100319/clean-c-backtrack-dp) |
| [496. Next Greater Element I](https://leetcode.com/problems/next-greater-element-i/description/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/496.%20Next%20Greater%20Element%20I.cpp) | Easy | Stack | [discuss](https://discuss.leetcode.com/topic/91234/c-o-n-time-o-1-space) |
| [498. Diagonal Traverse](https://leetcode.com/problems/diagonal-traverse/description/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/498.%20Diagonal%20Traverse.cpp) | Medium | Matrix | [discuss](https://discuss.leetcode.com/topic/105869/clean-c-recursion) |
| [499. The Maze III](https://leetcode.com/problems/the-maze-iii/description/) | [Solution](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/499.%20The%20Maze%20III.cpp) | Hard | DFS / BFS ||