GitHub - jssonx/algo-playground: optimize to push the limits.

Name		Name	Last commit message	Last commit date
Latest commit History 452 Commits
.github/workflows		.github/workflows
algo		algo
algorithms		algorithms
json		json
lc-cache		lc-cache
notes		notes
others		others
resources/images		resources/images
scripts		scripts
weekly-contest		weekly-contest
Makefile		Makefile
README.md		README.md
notes.md		notes.md
requirements.txt		requirements.txt

Repository files navigation

LeetCode Algorithms: By tags

Navigation

| Tree 60 | Array 40 | Binary-search 29 | Hash-table 26 | Depth-first-search 23 | String 23 | Two-pointers 22 | Dynamic-programming 21 | Math 16 | Stack 13 | Breadth-first-search 12 | Linked-list 12 | Bit-manipulation 8 | Sort 6 | Greedy 4 | Heap 4 | Sliding-window 4 | Backtracking 3 | Design 3 | Divide-and-conquer 3 | Graph 3 | Recursion 2 | Concurrency 1 | No-tags 1 | Ordered-map 1 | Topological-sort 1 | Trie 1 |

Template

Array

[2357.Make Array Zero by Subtracting Equal Amounts](Easy) - Python
[1480.Running Sum of 1d Array](Easy) - Python
[1002.Find Common Characters](Easy) - Java
[977.Squares of a Sorted Array](Easy) - Java Python
[905.Sort Array By Parity](Easy) - Python
[746.Min Cost Climbing Stairs](Easy) - Python
[724.Find Pivot Index](Easy) - Python
[717.1-bit and 2-bit Characters](Easy) - Python
[697.Degree of an Array](Easy) - Python
[509.Fibonacci Number](Easy) - Java Python
[422.Valid Word Square](Easy) - Python
[243.Shortest Word Distance](Easy) - Python
[228.Summary Ranges](Easy) - Python
[219.Contains Duplicate II](Easy) - Python
[217.Contains Duplicate](Easy) - Python
[119.Pascal's Triangle II](Easy) - Python
[35.Search Insert Position](Easy) - Python
[27.Remove Element](Easy) - Java Python
[1.Two Sum](Easy) - Java Python Rust
[670.Maximum Swap](Medium) - Python
[216.Combination Sum III](Medium) - Java
[209.Minimum Size Subarray Sum](Medium) - Java Python
[162.Find Peak Element](Medium) - Python
[153.Find Minimum in Rotated Sorted Array](Medium) - Python
[106.Construct Binary Tree from Inorder and Postorder Traversal](Medium) - Java Python
[105.Construct Binary Tree from Preorder and Inorder Traversal](Medium) - Python
[81.Search in Rotated Sorted Array II](Medium) - Python
[74.Search a 2D Matrix](Medium) - Python
[59.Spiral Matrix II](Medium) - Java
[55.Jump Game](Medium) - Python
[53.Maximum Subarray](Medium) - Python
[45.Jump Game II](Medium) - Python
[34.Find First and Last Position of Element in Sorted Array](Medium) - Python
[33.Search in Rotated Sorted Array](Medium) - Python
[31.Next Permutation](Medium) - Python
[18.4Sum](Medium) - Java
[16.3Sum Closest](Medium) - Python
[15.3Sum](Medium) - Java
[123.Best Time to Buy and Sell Stock III](Hard) - Python
[4.Median of Two Sorted Arrays](Hard) - Python

Backtracking

[216.Combination Sum III](Medium) - Java
[77.Combinations](Medium) - Java
[17.Letter Combinations of a Phone Number](Medium) - Java Python

Binary-search

[2389.Longest Subsequence With Limited Sum](Easy) - Python
[1539.Kth Missing Positive Number](Easy) - Python
[1337.The K Weakest Rows in a Matrix](Easy) - Python
[1150.Check If a Number Is Majority Element in a Sorted Array](Easy) - Python
[1099.Two Sum Less Than K](Easy) - Python
[744.Find Smallest Letter Greater Than Target](Easy) - Python
[704.Binary Search](Easy) - Java Python
[441.Arranging Coins](Easy) - Python
[374.Guess Number Higher or Lower](Easy) - Python
[367.Valid Perfect Square](Easy) - Python
[349.Intersection of Two Arrays](Easy) - Java Python
[278.First Bad Version](Easy) - Python
[270.Closest Binary Search Tree Value](Easy) - Python
[69.Sqrt(x)](Easy) - Python
[35.Search Insert Position](Easy) - Python
[1060.Missing Element in Sorted Array](Medium) - Python
[540.Single Element in a Sorted Array](Medium) - Python
[454.4Sum II](Medium) - Java
[240.Search a 2D Matrix II](Medium) - Python
[222.Count Complete Tree Nodes](Medium) - Java Python
[209.Minimum Size Subarray Sum](Medium) - Java Python
[162.Find Peak Element](Medium) - Python
[153.Find Minimum in Rotated Sorted Array](Medium) - Python
[81.Search in Rotated Sorted Array II](Medium) - Python
[74.Search a 2D Matrix](Medium) - Python
[34.Find First and Last Position of Element in Sorted Array](Medium) - Python
[33.Search in Rotated Sorted Array](Medium) - Python
[29.Divide Two Integers](Medium) - Python
[4.Median of Two Sorted Arrays](Hard) - Python

Bit-manipulation

[476.Number Complement](Easy) - Python
[342.Power of Four](Easy) - Python
[338.Counting Bits](Easy) - Python
[231.Power of Two](Easy) - Python
[191.Number of 1 Bits](Easy) - Python
[190.Reverse Bits](Easy) - Python
[136.Single Number](Easy) - Python
[187.Repeated DNA Sequences](Medium) - Python

Breadth-first-search

[111.Minimum Depth of Binary Tree](Easy) - Java Python
[101.Symmetric Tree](Easy) - Java Python
[1302.Deepest Leaves Sum](Medium) - Python
[743.Network Delay Time](Medium) - Python
[515.Find Largest Value in Each Tree Row](Medium) - Python
[513.Find Bottom Left Tree Value](Medium) - Java
[429.N-ary Tree Level Order Traversal](Medium) - Python
[286.Walls and Gates](Medium) - Python
[207.Course Schedule](Medium) - Python
[199.Binary Tree Right Side View](Medium) - Python
[107.Binary Tree Level Order Traversal II](Medium) - Python
[102.Binary Tree Level Order Traversal](Medium) - Java Python

Concurrency

[1195.Fizz Buzz Multithreaded](Medium) - Python

Depth-first-search

[257.Binary Tree Paths](Easy) - Java
[112.Path Sum](Easy) - Java Python
[111.Minimum Depth of Binary Tree](Easy) - Java Python
[110.Balanced Binary Tree](Easy) - Java Python
[108.Convert Sorted Array to Binary Search Tree](Easy) - Java
[104.Maximum Depth of Binary Tree](Easy) - Java Python
[101.Symmetric Tree](Easy) - Java Python
[100.Same Tree](Easy) - Java Python
[743.Network Delay Time](Medium) - Python
[515.Find Largest Value in Each Tree Row](Medium) - Python
[513.Find Bottom Left Tree Value](Medium) - Java
[394.Decode String](Medium) - Python
[366.Find Leaves of Binary Tree](Medium) - Python
[339.Nested List Weight Sum](Medium) - Python
[207.Course Schedule](Medium) - Python
[199.Binary Tree Right Side View](Medium) - Python
[129.Sum Root to Leaf Numbers](Medium) - Python
[117.Populating Next Right Pointers in Each Node II](Medium) - Python
[116.Populating Next Right Pointers in Each Node](Medium) - Python
[113.Path Sum II](Medium) - Python
[106.Construct Binary Tree from Inorder and Postorder Traversal](Medium) - Java Python
[105.Construct Binary Tree from Preorder and Inorder Traversal](Medium) - Python
[98.Validate Binary Search Tree](Medium) - Java

Design

[232.Implement Queue using Stacks](Easy) - Java
[225.Implement Stack using Queues](Easy) - Java
[707.Design Linked List](Medium) - Java

Divide-and-conquer

[240.Search a 2D Matrix II](Medium) - Python
[53.Maximum Subarray](Medium) - Python
[4.Median of Two Sorted Arrays](Hard) - Python

Dynamic-programming

[1137.N-th Tribonacci Number](Easy) - Python
[746.Min Cost Climbing Stairs](Easy) - Python
[338.Counting Bits](Easy) - Python
[303.Range Sum Query - Immutable](Easy) - Python
[70.Climbing Stairs](Easy) - Python
[1186.Maximum Subarray Sum with One Deletion](Medium) - Python
[740.Delete and Earn](Medium) - Python
[474.Ones and Zeroes](Medium) - Python
[376.Wiggle Subsequence](Medium) - Python
[309.Best Time to Buy and Sell Stock with Cooldown](Medium) - Python
[276.Paint Fence](Medium) - Python
[256.Paint House](Medium) - Python
[213.House Robber II](Medium) - Python
[198.House Robber](Medium) - Python
[96.Unique Binary Search Trees](Medium) - Python
[95.Unique Binary Search Trees II](Medium) - Python
[53.Maximum Subarray](Medium) - Python
[1289.Minimum Falling Path Sum II](Hard) - Python
[940.Distinct Subsequences II](Hard) - Python
[265.Paint House II](Hard) - Python
[123.Best Time to Buy and Sell Stock III](Hard) - Python

Graph

[1971.Find if Path Exists in Graph](Easy) - Python
[743.Network Delay Time](Medium) - Python
[207.Course Schedule](Medium) - Python

Greedy

[376.Wiggle Subsequence](Medium) - Python
[253.Meeting Rooms II](Medium) - Java
[55.Jump Game](Medium) - Python
[45.Jump Game II](Medium) - Python

Hash-table

[2357.Make Array Zero by Subtracting Equal Amounts](Easy) - Python
[1207.Unique Number of Occurrences](Easy) - Python
[1086.High Five](Easy) - Python
[1002.Find Common Characters](Easy) - Java
[734.Sentence Similarity](Easy) - Python
[697.Degree of an Array](Easy) - Python
[349.Intersection of Two Arrays](Easy) - Java Python
[290.Word Pattern](Easy) - Python
[266.Palindrome Permutation](Easy) - Java
[246.Strobogrammatic Number](Easy) - Python
[242.Valid Anagram](Easy) - Java
[219.Contains Duplicate II](Easy) - Python
[217.Contains Duplicate](Easy) - Python
[202.Happy Number](Easy) - Java
[136.Single Number](Easy) - Python
[94.Binary Tree Inorder Traversal](Easy) - Java Python
[20.Valid Parentheses](Easy) - Java Python
[1.Two Sum](Easy) - Java Python Rust
[454.4Sum II](Medium) - Java
[347.Top K Frequent Elements](Medium) - Java
[187.Repeated DNA Sequences](Medium) - Python
[159.Longest Substring with At Most Two Distinct Characters](Medium) - Python
[49.Group Anagrams](Medium) - Python
[18.4Sum](Medium) - Java
[3.Longest Substring Without Repeating Characters](Medium) - Python
[987.Vertical Order Traversal of a Binary Tree](Hard) - Python

Heap

[743.Network Delay Time](Medium) - Python
[347.Top K Frequent Elements](Medium) - Java
[253.Meeting Rooms II](Medium) - Java
[239.Sliding Window Maximum](Hard) - Java

Linked-list

[876.Middle of the Linked List](Easy) - Python
[234.Palindrome Linked List](Easy) - Python
[206.Reverse Linked List](Easy) - Java
[203.Remove Linked List Elements](Easy) - Java
[160.Intersection of Two Linked Lists](Easy) - Java
[21.Merge Two Sorted Lists](Easy) - Python
[707.Design Linked List](Medium) - Java
[142.Linked List Cycle II](Medium) - Java
[61.Rotate List](Medium) - Python
[24.Swap Nodes in Pairs](Medium) - Java
[19.Remove Nth Node From End of List](Medium) - Java Python
[2.Add Two Numbers](Medium) - Python

Math

[1523.Count Odd Numbers in an Interval Range](Easy) - Python
[1056.Confusing Number](Easy) - Python
[441.Arranging Coins](Easy) - Python
[367.Valid Perfect Square](Easy) - Python
[326.Power of Three](Easy) - Python
[258.Add Digits](Easy) - Python
[246.Strobogrammatic Number](Easy) - Python
[231.Power of Two](Easy) - Python
[202.Happy Number](Easy) - Java
[168.Excel Sheet Column Title](Easy) - Python
[69.Sqrt(x)](Easy) - Python
[670.Maximum Swap](Medium) - Python
[43.Multiply Strings](Medium) - Python
[29.Divide Two Integers](Medium) - Python
[2.Add Two Numbers](Medium) - Python
[224.Basic Calculator](Hard) - Python

No-tags

[1161.Maximum Level Sum of a Binary Tree](Medium) - Python

Ordered-map

[220.Contains Duplicate III](Hard) - Python

Recursion

[938.Range Sum of BST](Easy) - Python
[687.Longest Univalue Path](Medium) - Python

Sliding-window

[1151.Minimum Swaps to Group All 1's Together](Medium) - Python
[159.Longest Substring with At Most Two Distinct Characters](Medium) - Python
[3.Longest Substring Without Repeating Characters](Medium) - Python
[239.Sliding Window Maximum](Hard) - Java

Sort

[1337.The K Weakest Rows in a Matrix](Easy) - Python
[349.Intersection of Two Arrays](Easy) - Java Python
[242.Valid Anagram](Easy) - Java
[912.Sort an Array](Medium) - Java
[253.Meeting Rooms II](Medium) - Java
[220.Contains Duplicate III](Hard) - Python

Stack

[1469.Find All The Lonely Nodes](Easy) - Python
[1047.Remove All Adjacent Duplicates In String](Easy) - Java
[653.Two Sum IV - Input is a BST](Easy) - Python
[232.Implement Queue using Stacks](Easy) - Java
[225.Implement Stack using Queues](Easy) - Java
[145.Binary Tree Postorder Traversal](Easy) - Java Python
[144.Binary Tree Preorder Traversal](Easy) - Cpp Java Python
[94.Binary Tree Inorder Traversal](Easy) - Java Python
[20.Valid Parentheses](Easy) - Java Python
[394.Decode String](Medium) - Python
[150.Evaluate Reverse Polish Notation](Medium) - Java
[772.Basic Calculator III](Hard) - Python
[224.Basic Calculator](Hard) - Python

String

[1427.Perform String Shifts](Easy) - Python
[1065.Index Pairs of a String](Easy) - Python
[917.Reverse Only Letters](Easy) - Python
[606.Construct String from Binary Tree](Easy) - Python
[551.Student Attendance Record I](Easy) - Python
[459.Repeated Substring Pattern](Easy) - Java
[415.Add Strings](Easy) - Python
[383.Ransom Note](Easy) - Java
[344.Reverse String](Easy) - Java Python
[125.Valid Palindrome](Easy) - Python
[20.Valid Parentheses](Easy) - Java Python
[443.String Compression](Medium) - Python
[227.Basic Calculator II](Medium) - Python
[186.Reverse Words in a String II](Medium) - Python
[159.Longest Substring with At Most Two Distinct Characters](Medium) - Python
[151.Reverse Words in a String](Medium) - Java
[49.Group Anagrams](Medium) - Python
[43.Multiply Strings](Medium) - Python
[28.Find the Index of the First Occurrence in a String](Medium) - Java
[17.Letter Combinations of a Phone Number](Medium) - Java Python
[3.Longest Substring Without Repeating Characters](Medium) - Python
[772.Basic Calculator III](Hard) - Python
[214.Shortest Palindrome](Hard) - Python

Topological-sort

[207.Course Schedule](Medium) - Python

Tree

[1469.Find All The Lonely Nodes](Easy) - Python
[965.Univalued Binary Tree](Easy) - Python
[938.Range Sum of BST](Easy) - Python
[700.Search in a Binary Search Tree](Easy) - Java
[653.Two Sum IV - Input is a BST](Easy) - Python
[637.Average of Levels in Binary Tree](Easy) - Python
[617.Merge Two Binary Trees](Easy) - Java
[606.Construct String from Binary Tree](Easy) - Python
[590.N-ary Tree Postorder Traversal](Easy) - Python
[589.N-ary Tree Preorder Traversal](Easy) - Python
[572.Subtree of Another Tree](Easy) - Python
[563.Binary Tree Tilt](Easy) - Python
[530.Minimum Absolute Difference in BST](Easy) - Java
[501.Find Mode in Binary Search Tree](Easy) - Java
[404.Sum of Left Leaves](Easy) - Java
[270.Closest Binary Search Tree Value](Easy) - Python
[257.Binary Tree Paths](Easy) - Java
[226.Invert Binary Tree](Easy) - Java
[145.Binary Tree Postorder Traversal](Easy) - Java Python
[144.Binary Tree Preorder Traversal](Easy) - Cpp Java Python
[112.Path Sum](Easy) - Java Python
[111.Minimum Depth of Binary Tree](Easy) - Java Python
[110.Balanced Binary Tree](Easy) - Java Python
[108.Convert Sorted Array to Binary Search Tree](Easy) - Java
[104.Maximum Depth of Binary Tree](Easy) - Java Python
[101.Symmetric Tree](Easy) - Java Python
[100.Same Tree](Easy) - Java Python
[94.Binary Tree Inorder Traversal](Easy) - Java Python
[1302.Deepest Leaves Sum](Medium) - Python
[1008.Construct Binary Search Tree from Preorder Traversal](Medium) - Python
[958.Check Completeness of a Binary Tree](Medium) - Python
[889.Construct Binary Tree from Preorder and Postorder Traversal](Medium) - Python
[701.Insert into a Binary Search Tree](Medium) - Java
[687.Longest Univalue Path](Medium) - Python
[669.Trim a Binary Search Tree](Medium) - Java
[666.Path Sum IV](Medium) - Python
[654.Maximum Binary Tree](Medium) - Java
[538.Convert BST to Greater Tree](Medium) - Java
[515.Find Largest Value in Each Tree Row](Medium) - Python
[513.Find Bottom Left Tree Value](Medium) - Java
[450.Delete Node in a BST](Medium) - Java
[437.Path Sum III](Medium) - Python
[429.N-ary Tree Level Order Traversal](Medium) - Python
[366.Find Leaves of Binary Tree](Medium) - Python
[236.Lowest Common Ancestor of a Binary Tree](Medium) - Java
[235.Lowest Common Ancestor of a Binary Search Tree](Medium) - Java
[222.Count Complete Tree Nodes](Medium) - Java Python
[199.Binary Tree Right Side View](Medium) - Python
[129.Sum Root to Leaf Numbers](Medium) - Python
[117.Populating Next Right Pointers in Each Node II](Medium) - Python
[116.Populating Next Right Pointers in Each Node](Medium) - Python
[113.Path Sum II](Medium) - Python
[107.Binary Tree Level Order Traversal II](Medium) - Python
[106.Construct Binary Tree from Inorder and Postorder Traversal](Medium) - Java Python
[105.Construct Binary Tree from Preorder and Inorder Traversal](Medium) - Python
[102.Binary Tree Level Order Traversal](Medium) - Java Python
[98.Validate Binary Search Tree](Medium) - Java
[96.Unique Binary Search Trees](Medium) - Python
[95.Unique Binary Search Trees II](Medium) - Python
[987.Vertical Order Traversal of a Binary Tree](Hard) - Python

Trie

[1065.Index Pairs of a String](Easy) - Python

Two-pointers

[2540.Minimum Common Value](Easy) - Python
[977.Squares of a Sorted Array](Easy) - Java Python
[917.Reverse Only Letters](Easy) - Python
[905.Sort Array By Parity](Easy) - Python
[653.Two Sum IV - Input is a BST](Easy) - Python
[349.Intersection of Two Arrays](Easy) - Java Python
[344.Reverse String](Easy) - Java Python
[234.Palindrome Linked List](Easy) - Python
[125.Valid Palindrome](Easy) - Python
[27.Remove Element](Easy) - Java Python
[904.Fruit Into Baskets](Medium) - Java
[487.Max Consecutive Ones II](Medium) - Python
[209.Minimum Size Subarray Sum](Medium) - Java Python
[159.Longest Substring with At Most Two Distinct Characters](Medium) - Python
[142.Linked List Cycle II](Medium) - Java
[61.Rotate List](Medium) - Python
[28.Find the Index of the First Occurrence in a String](Medium) - Java
[19.Remove Nth Node From End of List](Medium) - Java Python
[18.4Sum](Medium) - Java
[16.3Sum Closest](Medium) - Python
[15.3Sum](Medium) - Java
[3.Longest Substring Without Repeating Characters](Medium) - Python

About

optimize to push the limits.

Report repository

Releases

No releases published

Packages

No packages published

Languages