Leetcode

Leetcode Question & Solutions

Binary Search 二分搜索

Leetcode 34 Find First and Last Position of Element in Sorted Array(Python)

Leetcode 35 Search Insert Position(Python)

Leetcode 704 Binary Search(Python)

Leetcode 875 Koko Eating Bananas(Python)

Leetcode 1011 Capacity To Ship Packages Within D Days(Python)

Leetcode 4 Median of Two Sorted Arrays

Leetcode 475 Heaters

Leetcode 162 Find Peak Element

Leetcode 875 Koko Eating Bananas

Leetcode 1011 Capacity To Ship Packages Within D Days

Leetcode 1060 Missing Element in Sorted Array

Leetcode 1539 Kth Missing Positive Number

Binary Tree 二叉树

Leetcode 95 Unique Binary Search Trees II(Python)

Leetcode 98 Validate Binary Search Tree

Leetcode 98 Validate Binary Search Tree(Python)

Leetcode 99 Recover Binary Search Tree

Leetcode 99 Recover Binary Search Tree(Python)

Leetcode 100 SameTree

Leetcode 100 SameTree(Python)

Leetcode 101 Symmetric Tree

Leetcode 101 Symmetric Tree(Python)

Leetcode 102 Binary Tree Level Order Traversal

Leetcode 102 Binary Tree Level Order Traversal(Python)

Leetcode 103 Binary Tree Zigzag Level Order Traversal

Leetcode 103 Binary Tree Zigzag Level Order Traversal(Python)

Leetcode 104 Maximum Depth of Binary Tree

Leetcode 666 Path Sum IV

Leetcode 104 Maximum Depth of Binary Tree(Python)

Leetcode 105 Construct Binary Tree from Preorder and Inorder Traversal

Leetcode 105 Construct Binary Tree from Preorder and Inorder Traversal(Python)

Leetcode 106 Construct Binary Tree from Inorder and Postorder Traversal

Leetcode 106 Construct Binary Tree from Inorder and Postorder Traversal(Python)

Leetcode 107 Binary Tree Level Order Traversal II(Python)

Leetcode 109 Convert Sorted List to Binary Search Tree(Python)

Leetcode 124 Binary Tree Maximum Path Sum

Leetcode 236 Lowest Common Ancestor of a Binary Tree

Leetcode 366 Find Leaves of Binary Tree

Leetcode 1644 Lowest Common Ancestor of a Binary Tree II

Leetcode 1650 Lowest Common Ancestor of a Binary Tree III

Leetcode 1676 Lowest Common Ancestor of a Binary Tree IV

Leetcode 272 Closest Binary Search Tree Value II

Leetcode 298 Binary Tree Longest Consecutive Sequence

Leetcode 314 Binary Tree Vertical Order Traversal

Leetcode 515 Find Largest Value in Each Tree Row

Leetcode 987 Vertical Order Traversal of a Binary Tree

Leetcode 530 Minimum Absolute Difference in BST

Leetcode 543 Diameter of Binary Tree

Leetcode 545 Boundary of Binary Tree

Leetcode 654 Maximum Binary Tree

Leetcode 1361 Validate Binary Tree Nodes

Leetcode 1660 Correct a Binary Tree

Leetcode 1666 Change the Root of a Binary Tree

Breadth-first search 广度优先搜索

Leetcode 111 Minimum Depth of Binary Tree

Leetcode 130 Surrounded Regions

Leetcode 210. Course Schedule II

Leetcode 513 Find Bottom Left Tree Value(TODO)

Leetcode 515 Find Largest Value in Each Tree Row

Leetcode 529 Minesweeper

Leetcode 785 Is Graph Bipartite?

Leetcode 994 Rotting Oranges

Leetcode 419 Battleships in a Board

Leetcode 815 Bus Routes

Leetcode 2115 Find All Possible Recipes from Given Supplies

Depth-first search 深度优先搜索

Leetcode 22 Generate Parentheses

Leetcode 39 Combination Sum

Leetcode 40 Combination Sum II

Leetcode 46 Permutations

Leetcode 47 Permutations II

Leetcode 51 N-Queens

Leetcode 77 Combinations

Leetcode 78 Subsets

Leetcode 79 Word Search

Leetcode 90 Subsets II

Leetcode 216 Combination Sum III

Leetcode 216 Combination Sum III

Leetcode 465 Optimal Account Balancing

Data Structure 数据结构

Leetcode 146 LRU Cache

Leetcode 460 LFU Cache

Design 设计类问题

Leetcode 348 Design Tic-Tac-Toe

Leetcode 588 Design In-Memory File System

LinkedList 链表问题

Leetcode 19 Remove Nth Node From End of List(Python)

Leetcode 21 Merge Two Sorted Lists(Python)

Leetcode 23 Merge k Sorted Lists(Python)

Leetcode 25 Reverse Linked List in K group

Leetcode 25 Reverse Linked List in K group(Python)

Leetcode 83 Remove Duplicates from Sorted List(Python)

Leetcode 92 Reverse Linked List II

Leetcode 92 Reverse Linked List II(Python)

Leetcode 141 Linked List Cycle(Python)

Leetcode 142 Linked List Cycle II(Python)

Leetcode 160 Intersection of Two Linked Lists(Python)

Leetcode 206 Reverse Linked List

Leetcode 206 Reverse Linked List(Python)

Leetcode 234 Palindrome Linked List

Leetcode 234 Palindrome Linked List

Leetcode 234 Palindrome Linked List(Python)

Prefix Sum Array 前缀和数组

Leetcode 303 Range Sum Query - Immutable

Leetcode 304 Range Sum Query 2D - Immutable

Leetcode 370 Range Addition

Leetcode 528 Random Pick with Weight

Leetcode 724 Find Pivot Index

Leetcode 930 Binary Subarrays With Sum

Leetcode 974 Subarray Sums Divisible by K

Leetcode 1109 Corporate Flight Bookings

Leetcode 1177 Can Make Palindrome from Substring

Leetcode 1413 Minimum Value to Get Positive Step by Step Sum

Leetcode 1422 Maximum Score After Splitting a String

Leetcode 1480 Running Sum of 1d Array

Leetcode 1588 Sum of All Odd Length Subarrays(This is not a easy, it is actually hard)

Leetcode 1732 Find the Highest Altitude

Leetcode 1893 Check if All the Integers in a Range Are Covered

Trie 前缀树

Leetcode 208 Implement Trie (Prefix Tree)

Leetcode 211 Design Add and Search Words Data Structure

Leetcode 648 Replace Words

Leetcode 677 Map Sum Pairs

Leetcode 1268 Search Suggestions System

Leetcode 1804 Implement Trie II (Prefix Tree)

Arrays 数组问题

Leetcode 1637 Widest Vertical Area Between Two Points Containing No Points

Two pointer 双指针问题

Arrays 数组应用

Leetcode 5 Longest Palindromic Substring

Leetcode 26 Remove Duplicates from Sorted Array

Leetcode 27 Remove Element

Leetcode 287 Find the Duplicate Number

Leetcode 283 Move zeros

Leetcode 2422 Merge Operations to Turn Array Into a Palindrome

LinkedList 链表应用

Leetcode 21 Merge Two Sorted Lists

Leetcode 23 Merge k Sorted Lists

Leetcode 19 Remove Nth Node From End of List

Leetcode 83 Remove Duplicates from Sorted List

Leetcode 876 Middle of the Linked List

Leetcode 141 Linked List Cycle

Leetcode 160 Intersection of Two Linked Lists

Sliding window 滑动窗口

Leetcode 3 Longest Substring Without Repeating Characters

Leetcode 424 Longest Repeating Character Replacement

Leetcode 76 Minimum Window Substring

Leetcode 239 Sliding Window Maximum

Leetcode 438 Find All Anagrams in a String

Leetcode 567 Permutation in String

Leetcode 1151 Minimum Swaps to Group All 1's Together

Monotonous stack 单调栈问题

Leetcode 84 Largest Rectangle in Histogram

Leetcode 739 Daily Temperatures

Leetcode 907 Sum of Subarray Minimums

Leetcode 503. Next Greater Element II

Leetcode 2104 Sum of Subarray Ranges

Stack 栈问题

Leetcode 20 Valid Parentheses

Leetcode 155 Min Stack

Leetcode 150 Evaluate Reverse Polish Notation

Leetcode 224 Basic Calculator

Leetcode 227 Basic Calculator II

Leetcode 772 Basic Calculator III

Greedy 贪心算法

Leetcode 1024 Video Stitching

DP 动态规划

House Robber Problem 打家劫舍问题

Buy and Sell Stock 股票买卖问题

Knapsack Problem 背包问题

Leetcode 72 Edit Distance

Leetcode 300 Longest increasing subsequence

Leetcode 583 Delete Operation for Two Strings

Leetcode 712 Minimum ASCII Delete Sum for Two Strings

Leetcode 907 Sum of Subarray Minimums

Leetcode 1143 Longest Common subsequence

Leetcode 1567 Maximum Length of Subarray With Positive Product

Graph 图算法

Floyd Algorithm 弗洛伊德算法

Leetcode 1334 Find the City With the Smallest...

Dijkstra Algorithm 迪杰斯特拉算法

Leetcode 734 Network Delay Time

Leetcode 1514 Path with Maximum Probability

Leetcode 1631 Path With Minimum Effort

BFS 广度优先搜索

Leetcode 210 Course Schedule II

DFS 深度优先搜索

Leetcode 207 Course Schedule

Leetcode 797 All Paths From Source to Target

Biparted Graph 二分图问题

Leetcode 785 Is Graph Bipartite?

Leetcode 886 Possible Bipartition

Celebrity Problem 名流问题

Leetcode 277 Find the Celebrity

UnionFind 并查集

Leetcode 261 Graph Valid Tree

Leetcode 323 Number of Connected Components in an Undirected Graph

Leetcode 547 Number of Provinces

Leetcode 924 Minimize malware

Leetcode 990 Satisfiability of Equality Equations

Leetcode 1135 Connecting Cities With Minimum Cost

Leetcode 1584 Min Cost to Connect All Points

String 字符串相关问题

Leetcode 161 One Edit Distance

Leetcode 299 Bulls and Cows

Leetcode 418 Sentence Screen Fitting

Leetcode 696 Count Binary Substrings

Leetcode 926 Count Binary Substrings

Leetcode 1758 Minimum Changes To Make Alternating Binary String

Leetcode 1864 Minimum Number of Swaps to Make the Binary String Alternating

Heap 堆相关问题

Leetcode 253 Meeting Rooms II

Leetcode 973 K Closest Points to Origin

Leetcode 1167 Minimum Cost to Connect Sticks

Leetcode 1353 Maximum Number of Events That Can Be Attended

Leetcode 2268 Minimum Number of Keypresses

SegmentTree 线段树

线段树模板