原文链接: https://leetcode-cn.com/problems/word-search 英文原文Given an m x n grid of characters board and a string word, return true if word exists in the grid. The word can be constructed from letters of sequentially adjacent cells, where adjacent cells ar…

原文链接: https://leetcode-cn.com/problems/remove-duplicates-from-sorted-array-ii 英文原文Given an integer array nums sorted in non-decreasing order, remove some duplicates in-place such that each unique element appears at most twice. The relative order of t…

原文链接: https://leetcode-cn.com/problems/remove-duplicates-from-sorted-list-ii 英文原文Given the head of a sorted linked list, delete all nodes that have duplicate numbers, leaving only distinct numbers from the original list. Return the linked list sorted…

原文链接: https://leetcode-cn.com/problems/remove-duplicates-from-sorted-list 英文原文Given the head of a sorted linked list, delete all duplicates such that each element appears only once. Return the linked list sorted as well. Example 1: Input: head = [1,1…

原文链接: https://leetcode-cn.com/problems/largest-rectangle-in-histogram 英文原文Given an array of integers heights representing the histogram's bar height where the width of each bar is 1, return the area of the largest rectangle in the histogram. Example …

原文链接: https://leetcode-cn.com/problems/maximal-rectangle 英文原文Given a rows x cols binary matrix filled with 0's and 1's, find the largest rectangle containing only 1's and return its area. Example 1: Input: matrix = [["1","0","1","0","0"],["1","0","1"…

原文链接: https://leetcode-cn.com/problems/partition-list 英文原文Given the head of a linked list and a value x, partition it such that all nodes less than x come before nodes greater than or equal to x. You should preserve the original relative order of the…

原文链接: https://leetcode-cn.com/problems/scramble-string 英文原文We can scramble a string s to get a string t using the following algorithm: If the length of the string is 1, stop. If the length of the string is > 1, do the following: Split the string into…

原文链接: https://leetcode-cn.com/problems/merge-sorted-array 英文原文You are given two integer arrays nums1 and nums2, sorted in non-decreasing order, and two integers m and n, representing the number of elements in nums1 and nums2 respectively. Merge nums1…

原文链接: https://leetcode-cn.com/problems/gray-code 英文原文An n-bit gray code sequence is a sequence of 2n integers where: Every integer is in the inclusive range [0, 2n - 1], The first integer is 0, An integer appears no more than once in the sequence, Th…

原文链接: https://leetcode-cn.com/problems/subsets-ii 英文原文Given an integer array nums that may contain duplicates, return all possible subsets (the power set). The solution set must not contain duplicate subsets. Return the solution in any order. Example…

原文链接: https://leetcode-cn.com/problems/decode-ways 英文原文A message containing letters from A-Z can be encoded into numbers using the following mapping: 'A' -> "1" 'B' -> "2" ... 'Z' -> "26" To decode an encoded message, all the digits must be grouped t…

原文链接: https://leetcode-cn.com/problems/restore-ip-addresses 英文原文A valid IP address consists of exactly four integers separated by single dots. Each integer is between 0 and 255 (inclusive) and cannot have leading zeros. For example, "0.1.2.201" and "…

原文链接: https://leetcode-cn.com/problems/binary-tree-inorder-traversal 英文原文Given the root of a binary tree, return the inorder traversal of its nodes' values. Example 1: Input: root = [1,null,2,3] Output: [1,3,2] Example 2: Input: root = [] Output: [] …

原文链接: https://leetcode-cn.com/problems/unique-binary-search-trees-ii 英文原文Given an integer n, return all the structurally unique BST's (binary search trees), which has exactly n nodes of unique values from 1 to n. Return the answer in any order. Examp…

原文链接: https://leetcode-cn.com/problems/unique-binary-search-trees 英文原文Given an integer n, return the number of structurally unique BST's (binary search trees) which has exactly n nodes of unique values from 1 to n. Example 1: Input: n = 3 Output: 5 E…

原文链接: https://leetcode-cn.com/problems/interleaving-string 英文原文Given strings s1, s2, and s3, find whether s3 is formed by an interleaving of s1 and s2. An interleaving of two strings s and t is a configuration where they are divided into non-empty su…

原文链接: https://leetcode-cn.com/problems/validate-binary-search-tree 英文原文Given the root of a binary tree, determine if it is a valid binary search tree (BST). A valid BST is defined as follows: The left subtree of a node contains only nodes with keys l…

原文链接: https://leetcode-cn.com/problems/recover-binary-search-tree 英文原文You are given the root of a binary search tree (BST), where the values of exactly two nodes of the tree were swapped by mistake. Recover the tree without changing its structure. Ex…

原文链接: https://leetcode-cn.com/problems/same-tree 英文原文Given the roots of two binary trees p and q, write a function to check if they are the same or not. Two binary trees are considered the same if they are structurally identical, and the nodes have t…

原文链接: https://leetcode-cn.com/problems/symmetric-tree 英文原文Given the root of a binary tree, check whether it is a mirror of itself (i.e., symmetric around its center). Example 1: Input: root = [1,2,2,3,4,4,3] Output: true Example 2: Input: root = [1,2…

原文链接: https://leetcode-cn.com/problems/binary-tree-level-order-traversal 英文原文Given the root of a binary tree, return the level order traversal of its nodes' values. (i.e., from left to right, level by level). Example 1: Input: root = [3,9,20,null,nul…

原文链接: https://leetcode-cn.com/problems/maximum-depth-of-binary-tree 英文原文Given the root of a binary tree, return its maximum depth. A binary tree's maximum depth is the number of nodes along the longest path from the root node down to the farthest lea…

原文链接: https://leetcode-cn.com/problems/construct-binary-tree-from-preorder-and-inorder-traversal 英文原文Given two integer arrays preorder and inorder where preorder is the preorder traversal of a binary tree and inorder is the inorder traversal of the s…

原文链接: https://leetcode-cn.com/problems/construct-binary-tree-from-inorder-and-postorder-traversal 英文原文Given two integer arrays inorder and postorder where inorder is the inorder traversal of a binary tree and postorder is the postorder traversal of t…

原文链接: https://leetcode-cn.com/problems/binary-tree-level-order-traversal-ii 英文原文Given the root of a binary tree, return the bottom-up level order traversal of its nodes' values. (i.e., from left to right, level by level from leaf to root). Example 1:…

原文链接: https://leetcode-cn.com/problems/convert-sorted-array-to-binary-search-tree 英文原文Given an integer array nums where the elements are sorted in ascending order, convert it to a height-balanced binary search tree. A height-balanced binary tree is a…

原文链接: https://leetcode-cn.com/problems/convert-sorted-list-to-binary-search-tree 英文原文Given the head of a singly linked list where elements are sorted in ascending order, convert it to a height balanced BST. For this problem, a height-balanced binary …

原文链接: https://leetcode-cn.com/problems/balanced-binary-tree 英文原文Given a binary tree, determine if it is height-balanced. For this problem, a height-balanced binary tree is defined as: a binary tree in which the left and right subtrees of every node d…

原文链接: https://leetcode-cn.com/problems/minimum-depth-of-binary-tree 英文原文Given a binary tree, find its minimum depth. The minimum depth is the number of nodes along the shortest path from the root node down to the nearest leaf node. Note: A leaf is a …