https://github.com/ololx/leetcode-solutions

This is my leetcode solutions repository
https://github.com/ololx/leetcode-solutions

algorithms algorithms-and-data-structures java leetcode leetcode-java leetcode-solutions solutions

Last synced: 28 days ago
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This is my leetcode solutions repository

• Host: GitHub
• URL: https://github.com/ololx/leetcode-solutions
• Owner: ololx
• License: unlicense
• Created: 2022-02-06T13:45:01.000Z (over 3 years ago)
• Default Branch: main
• Last Pushed: 2024-12-17T05:57:46.000Z (7 months ago)
• Last Synced: 2025-05-19T07:08:17.085Z (about 2 months ago)
• Topics: algorithms, algorithms-and-data-structures, java, leetcode, leetcode-java, leetcode-solutions, solutions
• Language: Java
• Homepage:
• Size: 814 KB
• Stars: 1
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# leetcode-solutions

This is a repository with my solutions to problems from www.leetcode.com.

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## Problems

  

    #

    Title

    Solution

    Difficulty

  

      

        1

        Decode XORed Array

        Solution

        EASY

    

    

        2

        Count Operations to Obtain Zero

        Solution

        EASY

    

    

        3

        Best Time to Buy and Sell Stock

        Solution

        EASY

    

    

        4

        Print in Order

        Solution

        EASY

    

    

        5

        Print in Order

        SolutionV3

        EASY

    

    

        6

        Print in Order

        SolutionV2

        EASY

    

    

        7

        Palindrome Number

        Solution

        EASY

    

    

        8

        Sum of Two Integers

        Solution

        EASY

    

    

        9

        Number of Even and Odd Bits

        Solution

        EASY

    

    

        10

        Pascals Triangle

        Solution

        EASY

    

    

        11

        Number of Steps to Reduce a Number to Zero

        Solution

        EASY

    

    

        12

        Buy Two Chocolates

        Solution

        EASY

    

    

        13

        Two Sum

        Solution

        EASY

    

    

        14

        Binary Tree Postorder Traversal

        Solution

        EASY

    

    

        15

        Squares of a Sorted Array

        Solution

        EASY

    

    

        16

        Remove Letter To Equalize Frequency

        Solution

        EASY

    

    

        17

        Plus One

        Solution

        EASY

    

    

        18

        Counter

        Solution.js

        EASY

    

    

        19

        Isomorphic Strings

        Solution

        EASY

    

    

        20

        Search Insert Position

        Solution

        EASY

    

    

        21

        Add Digits

        Solution

        EASY

    

    

        22

        Sqrt(x)

        Solution

        EASY

    

    

        23

        Length of Last Word

        Solution

        EASY

    

    

        24

        Island Perimeter

        Solution

        EASY

    

    

        25

        Island Perimeter

        SolutionV2

        EASY

    

    

        26

        Add Binary

        Solution

        EASY

    

    

        27

        Binary Tree Inorder Traversal

        Solution

        EASY

    

    

        28

        Implement Queue using Stacks

        Solution

        EASY

    

    

        29

        Nim Game

        Solution

        EASY

    

    

        30

        Find the Pivot Integer

        Solution

        EASY

    

    

        31

        Minimum Bit Flips to Convert Number

        Solution

        EASY

    

    

        32

        Missing Number

        Solution

        EASY

    

    

        33

        Missing Number

        SolutionV2

        EASY

    

    

        34

        Valid Parentheses

        Solution

        EASY

    

    

        35

        Backspace String Compare

        Solution

        EASY

    

    

        36

        Backspace String Compare

        SolutionV2

        EASY

    

    

        37

        Remove Element

        Solution

        EASY

    

    

        38

        Furthest Point From Origin

        Solution

        EASY

    

    

        39

        Add Strings

        Solution

        EASY

    

    

        40

        Running Sum of 1d Array

        Solution

        EASY

    

    

        41

        Fizz Buzz

        Solution

        EASY

    

    

        42

        Valid Palindrome II

        Solution

        EASY

    

    

        43

        Contains Duplicate II

        Solution

        EASY

    

    

        44

        Contains Duplicate II

        SolutionV2

        EASY

    

    

        45

        Implement strStr()

        Solution

        EASY

    

    

        46

        Implement strStr()

        SolutionV2

        EASY

    

    

        47

        Average Value of Even Numbers That Are Divisible by Three

        Solution

        EASY

    

    

        48

        Valid Anagram

        Solution

        EASY

    

    

        49

        Remove Duplicates from Sorted Array

        Solution

        EASY

    

    

        50

        Reverse Prefix of Word

        Solution

        EASY

    

    

        51

        Merge Two Sorted Lists

        Solution

        EASY

    

    

        52

        Maximum Average Subarray I

        Solution

        EASY

    

    

        53

        Maximum Average Subarray I

        SolutionV2

        EASY

    

    

        54

        Number Complement

        Solution

        EASY

    

    

        55

        Merge Sorted Array

        Solution

        EASY

    

    

        56

        Crawler Log Folder

        Solution

        EASY

    

    

        57

        Majority Element

        Solution

        EASY

    

    

        58

        Majority Element

        SolutionV2

        EASY

    

    

        59

        Merge Strings Alternately

        Solution

        EASY

    

    

        60

        A Number After a Double Reversal

        Solution

        EASY

    

    

        61

        Reverse Words in a String III

        Solution

        EASY

    

    

        62

        Reverse Words in a String III

        SolutionV2

        EASY

    

    

        63

        Sort Integers by The Number of 1 Bits

        Solution

        EASY

    

    

        64

        Excel Sheet Column Title

        Solution

        EASY

    

    

        65

        Design HashMap

        Solution

        EASY

    

    

        66

        Sum of Squares of Special Elements

        Solution

        EASY

    

    

        67

        Maximum Depth of Binary Tree

        Solution

        EASY

    

    

        68

        Maximum Length Substring With Two Occurrences

        Solution

        EASY

    

    

        69

        Counting Bits

        Solution

        EASY

    

    

        70

        Counting Bits

        SolutionV2

        EASY

    

    

        71

        Find First Palindromic String in the Array

        Solution

        EASY

    

    

        72

        Reverse String

        Solution

        EASY

    

    

        73

        Excel Sheet Column Number

        Solution

        EASY

    

    

        74

        Valid Palindrome

        Solution

        EASY

    

    

        75

        Reverse String II

        Solution

        EASY

    

    

        76

        Reverse String II

        SolutionV2

        EASY

    

    

        77

        First Letter to Appear Twice

        Solution

        EASY

    

    

        78

        Linked List Cycle

        Solution

        EASY

    

    

        79

        UNKNOWN

        Solution

        EASY

    

    

        80

        Divide a String Into Groups of Size k

        Solution

        EASY

    

    

        81

        Power of Four

        Solution

        EASY

    

    

        82

        Find the Difference

        Solution

        EASY

    

    

        83

        Find Smallest Letter Greater Than Target

        Solution

        EASY

    

    

        84

        Find Smallest Letter Greater Than Target

        SolutionV2

        EASY

    

    

        85

        Path Sum

        Solution

        EASY

    

    

        86

        Word Pattern

        Solution

        EASY

    

    

        87

        Hamming Distance

        Solution

        EASY

    

    

        88

        Hamming Distance

        SolutionV3

        EASY

    

    

        89

        Hamming Distance

        SolutionV2

        EASY

    

    

        90

        Construct the Rectangle

        Solution

        EASY

    

    

        91

        Reverse Linked List

        Solution

        EASY

    

    

        92

        Positions of Large Groups

        Solution

        EASY

    

    

        93

        Positions of Large Groups

        SolutionV2

        EASY

    

    

        94

        Number of Segments in a String

        Solution

        EASY

    

    

        95

        Complement of Base 10 Integer

        Solution

        EASY

    

    

        96

        Reformat Phone Number

        Solution

        EASY

    

    

        97

        Number of Unequal Triplets in Array

        Solution

        EASY

    

    

        98

        Check if Numbers Are Ascending in a Sentence

        Solution

        EASY

    

    

        99

        Power of Two

        Solution

        EASY

    

    

        100

        Power of Two

        SolutionV2

        EASY

    

    

        101

        Check if Number Has Equal Digit Count and Digit Value

        Solution

        EASY

    

    

        102

        Most Frequent Even Element

        Solution

        EASY

    

    

        103

        Remove Duplicates from Sorted List

        Solution

        EASY

    

    

        104

        Implement Stack using Queues

        Solution

        EASY

    

    

        105

        First Bad Version

        Solution

        EASY

    

    

        106

        Counter II

        Solution.js

        EASY

    

    

        107

        Baseball Game

        Solution

        EASY

    

    

        108

        Roman to Integer

        Solution

        EASY

    

    

        109

        Convert the Temperature

        Solution

        EASY

    

    

        110

        Longest Common Prefix

        Solution

        EASY

    

    

        111

        Move Zeroes

        Solution

        EASY

    

    

        112

        Symmetric Tree

        Solution

        EASY

    

    

        113

        Min Stack

        Solution

        EASY

    

    

        114

        Min Stack

        SolutionV2

        EASY

    

    

        115

        Fibonacci Number

        Solution

        EASY

    

    

        116

        Binary Search

        Solution

        EASY

    

    

        117

        Rearrange Spaces Between Words

        Solution

        EASY

    

    

        118

        Reverse Bits

        Solution

        EASY

    

    

        119

        Same Tree

        Solution

        EASY

    

    

        120

        Range Sum Query - Immutable

        Solution

        EASY

    

    

        121

        Single Number

        Solution

        EASY

    

    

        122

        Single Number

        SolutionV2

        EASY

    

    

        123

        Count Good Triplets

        Solution

        EASY

    

    

        124

        Check if All As Appears Before All Bs

        Solution

        EASY

    

    

        125

        Number of 1 Bits

        Solution

        EASY

    

    

        126

        Design HashSet

        Solution

        EASY

    

    

        127

        Is Subsequence

        Solution

        EASY

    

    

        128

        Text Justification

        Solution

        HARD

    

    

        129

        Design Skiplist

        Solution

        HARD

    

    

        130

        Valid Number

        Solution

        HARD

    

    

        131

        LFU Cache

        Solution

        HARD

    

    

        132

        Design a Text Editor

        Solution

        HARD

    

    

        133

        Reverse Integer

        Solution

        MEDIUM

    

    

        134

        UNKNOWN

        Solution

        MEDIUM

    

    

        135

        Validate Stack Sequences

        Solution

        MEDIUM

    

    

        136

        Zigzag Conversion

        Solution

        MEDIUM

    

    

        137

        Flatten Nested List Iterator

        Solution

        MEDIUM

    

    

        138

        Binary Search Tree Iterator

        Solution

        MEDIUM

    

    

        139

        String to Integer (atoi)

        Solution

        MEDIUM

    

    

        140

        Print FooBar Alternately

        Solution

        MEDIUM

    

    

        141

        Rotate List

        Solution

        MEDIUM

    

    

        142

        Spiral Matrix II

        Solution

        MEDIUM

    

    

        143

        Spiral Matrix II

        SolutionV2

        MEDIUM

    

    

        144

        UNKNOWN

        Solution

        MEDIUM

    

    

        145

        Single Number III

        Solution

        MEDIUM

    

    

        146

        Score of Parentheses

        Solution

        MEDIUM

    

    

        147

        Container With Most Water

        Solution

        MEDIUM

    

    

        148

        Max Number of K-Sum Pairs

        Solution

        MEDIUM

    

    

        149

        Minimum Remove to Make Valid Parentheses

        Solution

        MEDIUM

    

    

        150

        Jump Game II

        Solution

        MEDIUM

    

    

        151

        K Radius Subarray Averages

        Solution

        MEDIUM

    

    

        152

        Search a 2D Matrix

        Solution

        MEDIUM

    

    

        153

        Search a 2D Matrix

        SolutionV2

        MEDIUM

    

    

        154

        Remove Nth Node From End of List

        Solution

        MEDIUM

    

    

        155

        H-Index

        Solution

        MEDIUM

    

    

        156

        Find the Duplicate Number

        Solution

        MEDIUM

    

    

        157

        Majority Element II

        Solution

        MEDIUM

    

    

        158

        Encode and Decode TinyURL

        Solution

        MEDIUM

    

    

        159

        Maximum Depth of N-ary Tree

        Solution

        MEDIUM

    

    

        160

        Evaluate Reverse Polish Notation

        Solution

        MEDIUM

    

    

        161

        Building H2O

        Solution

        MEDIUM

    

    

        162

        Longest Substring Without Repeating Characters

        Solution

        MEDIUM

    

    

        163

        Longest Substring Without Repeating Characters

        SolutionV2

        MEDIUM

    

    

        164

        Flatten Binary Tree to Linked List

        Solution

        MEDIUM

    

    

        165

        Find the Longest Substring Containing Vowels in Even Counts

        Solution

        MEDIUM

    

    

        166

        Add Two Numbers

        Solution

        MEDIUM

    

    

        167

        LRU Cache

        Solution

        MEDIUM

    

    

        168

        Print Zero Even Odd

        Solution

        MEDIUM

    

    

        169

        Unique Paths

        Solution

        MEDIUM

    

    

        170

        Spiral Matrix

        SolutionV2

        MEDIUM

    

    

        171

        Append Characters to String to Make Subsequence

        Solution

        MEDIUM

    

    

        172

        Number of Islands

        Solution

        MEDIUM

    

    

        173

        Jump Game

        Solution

        MEDIUM

    

    

        174

        Unique Paths II

        Solution

        MEDIUM

    

    

        175

        Minimum Path Sum

        Solution

        MEDIUM

    

    

        176

        Map Sum Pairs

        Solution

        MEDIUM

    

    

        177

        Rotate Image

        Solution

        MEDIUM

    

    

        178

        Swap Nodes in Pairs

        Solution

        MEDIUM

    

    

        179

        Integer to Roman

        Solution

        MEDIUM

    

    

        180

        Simplify Path

        Solution

        MEDIUM

    

    

        181

        Remove Duplicates from Sorted List II

        Solution

        MEDIUM

    

    

        182

        Find The Original Array of Prefix Xor

        Solution

        MEDIUM

    

    

        183

        Peeking Iterator

        Solution

        MEDIUM

    

    

        184

        Peeking Iterator

        SolutionV2

        MEDIUM

    

    

        185

        Number of Matching Subsequences

        Solution

        MEDIUM

    

    

        186

        UTF-8 Validation

        Solution

        MEDIUM

    

    

        187

        Jump Game III

        Solution

        MEDIUM

    

    

        188

        Fizz Buzz Multithreaded

        Solution

        MEDIUM

    

    

        189

        Range Sum Query 2D - Immutable

        Solution

        MEDIUM

    

    

        190

        House Robber

        Solution

        MEDIUM

    

    

        191

        House Robber

        SolutionV2

        MEDIUM