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