Algorithm Exercises

Algorithm exercises from LeetCode implemented in Java v11.

Solutions

String

• Sorting Sentence | Problem | Solution
• Student Attendance Record I | Problem | Solution
• Reverse Words in a String III | Problem | Solution
• One Edit Distance | Problem | Solution
• Find And Replace in String | Problem | Solution

Array

• Jewels and Stones | Problem | Solution
• Rings and Rods | Problem | Solution
• Concatenation of Array | Problem | Solution
• Find Target Indices After Sorting Array | Problem | Solution
• Running Sum of Array | Problem | Solution
• Parking System | Problem | Solution

Matrix

• Max Increase to Keep City Skyline | Problem | Solution
• Cells with Odd Values in a Matrix | Problem | Solution
• Island Perimeter | Problem | Solution
• Valid Sudoku | Problem | Solution
• Where Will the Ball Fall | Problem | Solution
• Remove All Ones With Row and Column Flips | Problem | Solution

HashTable

• Two Sum | Problem | Solution
• Destination City | Problem | Solution
• Number of Good Pairs | Problem | Solution
• Logger Rate Limiter | Problem | Solution
• Unique Number of Occurrences | Problem | Solution
• Snapshot Array | Problem | Solution

Stack

• Min Stack | Problem | Solution
• Valid Parentheses | Problem | Solution
• Decode String | Problem | Solution
• Simplify Path | Problem | Solution
• Longest Absolute File Path | Problem | Solution
• Remove All Adjacent Duplicates In String | Problem | Solution
• Binary Tree Inorder Traversal | Problem | Solution
• Evaluate Reverse Polish Notation | Problem | Solution
• Basic Calculator | Problem | Solution

Queue

• Queue Using Stacks | Problem | Solution

Heap

• Top Kth Frequent Elements | Problem | Solution
• Kth Largest Elements | Problem | Solution
• Meeting Rooms II | Problem | Solution
• Find Median From Data Stream | Problem | Solution
• Stock Price Fluctuation | Problem | Solution
• Design Twitter | Problem | Solution
• Employee Free Time | Problem | Solution
• Process Tasks Using Servers | Problem | Solution

LinkedList

• Lowest Common Ancestor Of Binary Tree III | Problem | Solution
• Browser History | Problem | Solution
• LRU Cache | Problem | Solution
• LFU Cache | Problem | Solution
• Add Two Numbers | Problem | Solution
• Insertion Sort List | Problem | Solution
• Insert into a Sorted Circular Linked List | Problem | Solution

Trie

• Implement Trie (Prefix Tree) | Problem | Solution
• Implement Trie II (Prefix Tree) | Problem | Solution

Sorting

• Meeting Rooms | Problem | Solution
• Merge Intervals | Problem | Solution
• Group Anagrams | Problem | Solution
• Minimum Time Difference | Problem | Solution

Binary Search

• Convert Sorted Array To BST | Problem | Solution
• Peak Index in a Mountain Array | Problem | Solution

Two Pointers

• First Unique Character | Problem | Solution
• Valid Palindrome | Problem | Solution
• Is Subsequence | Problem
• Squares of a Sorted Array | Problem
• Sort Array By Parity | Problem | Solution
• Minimize Maximum Pair Sum | Problem | Solution
• Merge Sorted Array | Problem | Solution
• Partition Labels | Problem | Solution
• Meeting Scheduler | Problem | Solution
• Expressive Words | Problem | Solution
• Longest Word in Dictionary through Deleting | Problem | Solution
• Swap Adjacent in LR String | Problem | Solution

Sliding Window

• Minimum Size Subarray Sum | Problem | Solution
• Binary Subarrays With Sum | Problem | Solution
• Maximum Points You Can Obtain from Cards | Problem | Solution
• Longest Substring Without Repeating Characters | Problem | Solution
• Sliding Window Maximum | Problem | Solution

Prefix Sum

• Product of the Last K Numbers | Problem | Solution
• Substrings That Begin and End With the Same Letter | Problem | Solution
• Subarray Sum Equals K | Problem | Solution

Recursion

• Closest Binary Search Tree Value | Problem
• Subtree Of Another Tree | Problem | Solution
• Climbing Stairs | Problem | Solution
• All Possible Full Binary Trees | Problem | Solution
• Different Ways to Add Parentheses | Problem | Solution

BFS

• Binary Tree Level Inorder Traversal | Problem | Solution
• Binary Tree Zigzag Level Order Traversal | Problem | Solution
• Binary Tree Right Side View | Problem | Solution
• Shortest Path in Binary Matrix | Problem | Solution
• Shortest Path to Get Food | Problem | Solution
• Shortest Distance from All Buildings | Problem | Solution
• Find if Path Exists in Graph | Problem | Solution
• Path with Maximum Probability | Problem | Solution

DFS

• Path Sum | Problem
• Path Sum II | Problem
• Find Leaves of Binary Tree | Problem | Solution
• Delete Leaves With a Given Value | Problem | Solution
• All Paths From Source to Target | Problem | Solution
• Count Univalue Subtrees | Problem | Solution
• Delete Nodes And Return Forest | Problem | Solution
• Maximum Product of Split Binary Tree | Problem | Solution
• Number of Islands | Problem | Solution
• Battleships in a Board | Problem | Solution

Backtracking

• Combinations | Problem | Solution
• Permutations | Problem | Solution
• Letter Combinations of a Phone Number | Problem | Solution
• Combination Sum | Problem | Solution
• Generate Parentheses | Problem | Solution
• Word Search | Problem | Solution
• Word Search II | Problem | Solution
• Sudoku Solver | Problem | Solution
• Expression Add Operators | Problem | Solution

Topological Sort

• Course Schedule | Problem | Solution
• Course Schedule II | Problem | Solution
• Find All Possible Recipes from Given Supplies | Problem | Solution

Bit Manipulation

• Single Number | Problem | Solution
• Subsets | Problem | Solution
• Hamming Distance | Problem | Solution
• Counting Bits | Problem | Solution

Dynamic Programming

• Best Sightseeing Pair | Problem | Solution
• Minimum Path Sum | Problem | Solution
• Minimum Falling Path Sum | Problem | Solution
• Maximum Number of Points with Cost | Problem | Solution
• Count Sorted Vowel Strings | Problem | Solution
• Count Square Submatrices with All Ones | Problem | Solution
• Partition Equal Subset Sum | Problem | Solution