https://github.com/chiphuyen/coding-exercises
My implementation of useful data structures, algorithms, as well as my solutions to programming puzzles.
https://github.com/chiphuyen/coding-exercises
coding-challenge coding-exercises coding-interviews training-materials
Last synced: about 2 months ago
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My implementation of useful data structures, algorithms, as well as my solutions to programming puzzles.
- Host: GitHub
- URL: https://github.com/chiphuyen/coding-exercises
- Owner: chiphuyen
- Created: 2017-11-19T08:06:58.000Z (over 7 years ago)
- Default Branch: master
- Last Pushed: 2019-11-21T04:14:33.000Z (over 5 years ago)
- Last Synced: 2025-03-29T06:06:53.425Z (about 2 months ago)
- Topics: coding-challenge, coding-exercises, coding-interviews, training-materials
- Language: Python
- Homepage:
- Size: 466 KB
- Stars: 497
- Watchers: 38
- Forks: 194
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
Awesome Lists containing this project
README
This repository contains my implementation of useful data structures, algorithms,
games, as well as my solutions to programming puzzles.
Each item is marked with a difficulty level.
1 - easy
2 - medium
3 - hard
If a file name starts with 'lc', it's a problem from leetcode.com
Written in python3. Thanks Danijar Hafner (@danijar) for the inspiration.
Data structures
---------------
### Linked lists
- [x] List class (linked_list.py) - 1
- [ ] Remove duplicates (linked_list_algos.py)
- [ ] Find nth last element (linked_list_algos.py)
- [ ] Remove node given only its object (linked_list_algos.py)
- [ ] Sum linked lists with one digit per node (linked_list_algos.py)
- [ ] Find beginning of circle (linked_list_algos.py)
### Trees
- [x] Binary heap class (binary_heap.py) - 2
- [ ] Binary tree class (binary_tree.py) - 1
- [x] Binary search tree class that allows duplicate values (binary_search_tree.py) - 2
BST class inherits binary tree class
- [ ] Red black tree class (red_black_tree.py)
- [ ] B+ tree class (b_tree.py) - 3
- [x] Trie class that allows word removal (trie.py) - 2
- [x] Check if a binary tree is a binary search tree (binary_tree_algos.py) - 2
- [ ] Check if a binary tree is balanced (binary_tree_algos.py)
- [ ] Find first common ancestor of two nodes in a binary tree (binary_tree_algos.py)
- [ ] Get all nodes of depth n in a binary tree (binary_tree_algos.py)
- [ ] Given two large trees, check if the first is a subtree of the second (binary_tree_algos.py)
- [ ] Find all sub paths in a binary tree that sum up to x (binary_tree_algos.py)
- [ ] Create a balanced binary search tree from a sorted array (bst_algos.py)
### Graphs
- [ ] Undirected graph class
- [ ] Directed graph class
- [ ] Breadth first search (search.py)
- [ ] Depth first search (search.py)
- [ ] A-star (search.py)
### Stacks and queues
- [ ] Queue class (queue.py)
- [x] Heap priority queue (priority_queue.py) - 1
- [ ] Stack class (stack.py)
- [ ] Stack that finds min in O(1) (min_stack.py)
- [ ] Solve Hanoi towers using stacks (stack_algos.py)
- [ ] Sort stack using only push, pop, peek and empty (stack_algos.py)
- [ ] Build a queue using two stacks (stack_algos.py)
Algorithms
----------
### Sorting
- [x] Insertion sort (sort.py) - 1
- [x] Selection sort (sort.py) - 1
- [x] Merge sort (sort.py) - 2
- [x] Heap sort (sort.py) - 2
- [x] Quick sort (sort.py) - 2
- [x] Counting sort (sort.py) - 2
- [x] Radix sort (sort.py) - 2
- [x] Bucket sort (sort.py) - 2
### Dynamic Programming
- [ ] Computing a Fibonacci sequence
- [ ] Find the longest common subsequence between two strings
### Recursion
- [ ] Find all permutations of a string
- [ ] Find all subsets of a set
- [ ] Find all proper combinations of n parentheses
- [ ] Bucket fill
- [ ] Check if it's possible to make a change with a set of coins
- [ ] Check if it's possible to weight two objects with a set of weights
- [ ] Eight queen
Programming Puzzles
-------------------
### String Manipulation
- [x] Check if two strings are anagrams in O(n + m) time (anagrams.py) - 1
- [x] Find the longest palindromic substring in O(n^2) time (lc_longest_palindrome.py) - 2
- [x] Check if a string has balanced delimiters in O(n) time (delim_balanced.py) - 2
- [x] Reverse words while maintaining spaces and tabs in O(n) time (reverse_words.py) - 2
- [x] Longest substring without repeating characters in O(n) time (lc_longest_nonrepeat_substring.py) - 2
- [x] Longest contiguous substring of 2 distinct characters in O(n) time (substring_two_chars.py) - 2
- [ ] Remove duplicate chars in a string
- [ ] Encode and decode Caesar cipher (caesar.py)
- [ ] Check if a string is a rotation of another
### Mathematical
- [x] Reverse integers (lc_reverse_int.py) - 1
- [x] Sieve of Eratosthenes (sieve_prime.py) - 1
- [x] Two sum in O(n) time (lc_two_sum.py) - 1
Given an array of integers, return indices of the two numbers
such that they add up to a specific target.
- [x] Year with maximum population (year_max_pop.py) - 1
Given a list of people with their years of birth and death,
find the year with max population
- [x] FizzBuzz (fizzbuzz.py) - 1
- [x] ZigZag conversion (lc_zigzag_convert.py) - 2
- [x] Find sum of all subarrays of an array (subarray_sum.py) - 2
- [x] Add two numbers, each represented by a reverse linked list (lc_add_number_reverse.py) - 2
- [x] Find the median of two sorted arrays in O(log(m+n)) time (lc_median_arrays.py) - 3
- [ ] Find nth smallest number that can be created using a list of prime factors
- [ ] Count occurences of given digit in all numbers up to n
- [ ] Rotate N x N matrix in place
### Games
- [x] Game of ghost (ghost.py) - 3
Ghost is a word game in which players take turns adding letters to a
growing word fragment, trying not to be the one to complete a valid word.
This implementation uses minimax with alpha-beta pruning to make sure the computer always wins.
It uses a Trie to keep track of the dictionary.