andreimaximov / algorithms

HackerRank, Codeforces, Geeks for Geeks, and LeetCode problem solutions

README

This is a collection of my HackerRank, Codeforces, Geeks for Geeks, and LeetCode problem solutions in C++, Java, and Python 3. These are not meant to be competition style implementations but clean and easily understandable algorithms for learning purposes.

HackerRank

• Algorithms
  • Bit Manipulation
    • AND Product
    • Cipher
    • Flipping Bits
  • Dynamic Programming
    • Candies
    • The Coin Change Problem
    • Fibonacci Modified
    • Grid Walking
    • Longest Common Subsequence
    • Longest Increasing Subsequence
    • Maximum Subarray
    • Square Subsequences
    • Stock Maximize
    • Summing Pieces
  • Graph Theory
    • BFS: Shortest Reach
    • Crab Graphs
    • Dijkstra: Shortest Reach 2
    • Floyd: City of Blinding Lights
    • Jack goes to Rapture
    • Journey to the Moon
    • Kruskal (MST): Really Special Subtree
    • Prim's (MST): Special Subtree
    • SCC
  • Implementation
    • Matrix Rotation
  • Search
    • Connected Cell in a Grid
    • Cut the Tree
    • Max Sum K Non-Adjacent
    • Maximise Sum
    • Missing Numbers
    • Pairs
    • Playing With Numbers
    • Sherlock and Array
    • Short Palindrome
  • Sorting
    • Quicksort In-Place
  • Strings
    • Bigger is Greater
    • Common Child
    • Pangrams
    • Sherlock and Anagrams
    • Two Strings
• Artificial Intelligence
  • Tic Tac Toe
• Data Structures
  • Disjoint Set
    • Merging Communities
  • Heap
    • Find Median
  • Tree
    • BST: Lowest Common Ancestor
    • Median Updates
    • Self Balancing Tree
  • Trie
    • No Prefix Set
• Mathematics
  • Combinatorics
    • Choose and Calculate
    • Journey to Mars
    • nCr Table
    • Rank of a Word

CodeForces

• 229D Towers
• 276C Little Girl and Maximum Sum
• 342E Xenia and Tree
• 547B Mike and Feet
• 637D Running with Obstacles
• 749D Leaving Auction
• 750D New Year and Fireworks
• 753B Interactive Bulls and Cows (Easy)
• 753C Interactive Bulls and Cows (Hard)
• 754D Fedor and Coupons
• 758D Ability To Convert
• 758E Broken Tree
• 758F Geometric Progression
• 780D Innokenty and a Football League
• 780E Underground Lab
• 792D Paths in a Complete Binary Tree
• 796D Police Stations
• 796E Exam Cheating
• 815C Karen and Supermarket
• 818D Multicolored Cars
• 819B Mister B and PR Shifts
• 819E Mister B and Flight to the Moon
• 827C DNA Evolution
• 830B Cards Sorting
• 833B The Bakery
• 835E The Penguin's Game

Geeks for Geeks

• Dynamic Programming
  • Set 18 - Partition Problem
• Mathematics
  • Weighted Random Generator
• Linked List
  • Flatten Multi Level Linked List

LeetCode

• Algorithms
  • 4Sum
  • Basic Calculator
  • Preorder and Inorder Traversal
  • Postorder and Inorder Traversal
  • Binary Tree Maximum Path Sum
  • Binary Tree Zigzag Level Order Traversal
  • Burst Balloons
  • Closest Palindrome
  • Container With Most Water
  • Contains Duplicate III
  • Data Stream as Disjoint Intervals
  • Difference Ways to Add Parenthesis
  • Distinct Subsequences
  • Dungeon Game
  • Edit Distance
  • Encode String with Shortest Length
  • Flatten Binary Tree to Linked List
  • Game of Life
  • Gas Station
  • Interleaving String
  • Is Balanced
  • K Pairs with Smallest Sums
  • Kth Largest Element
  • Kth Smallest Element in Sorted Matrix
  • Largest Rectangle in Histogram
  • LCA of a Binary Tree
  • Lexicographical Numbers
  • LFU Cache
  • Linked List Cycle II
  • Longest Valid Parenthesis
  • Majority Element II
  • Max Points on a Line
  • Maximum Gap
  • Median of Two Sorted Arrays
  • Mini Parser
  • Minimum Height Tree
  • Minimum Window Substring
  • N-Queens II
  • Non Overlapping Intervals
  • Palindrome Linked List
  • Palindrome Pairs
  • Permutation Sequence
  • Permutations II
  • Range Sum Query - Mutable
  • Recover Binary Tree
  • Rectangle Area
  • Regular Expression Matching
  • Remove Duplicates from Sorted Array II
  • Remove K Digits
  • Reverse Nodes in k-Group
  • Reverse Words in a String
  • Rotate Image
  • Set Matrix Zeroes
  • Skyline
  • Sliding Window Maximum
  • Shortest Palindrome
  • Sorted Array to BST
  • Spiral Matrix
  • Sqrt(x)
  • Stock Profit III
  • Stock Profit IV
  • Subsets II
  • Substring with Concatenation of All Words
  • Sudoku Solver
  • Unique Substrings in Wraparound String
  • Validate BST
  • Wiggle Subsequence
  • Wildcard Matching
  • Word Break