给定一个非负整数数组nums和一个整数m ，你需要将这个数组分成m个非空的连续子数组。 设计一个算法使得这m个子数组各自和的最大值最小。
给你一个由若干括号和字母组成的字符串 s ，删除最小数量的无效括号，使得输入的字符串有效。 返回所有可能的结果。答案可以按任意顺序返回。
Given an m x n grid of characters board and a string word, return true if word exists in the grid.
LinkedList - 25. Reverse Nodes in k-Group
Given a linked list, reverse the nodes of a linked list k at a time and return its modified list.
1143. Longest Common Subsequence
Given two strings text1 and text2, return common subsequence. If there is no common subsequence, return 0.
Array - 88. Merge Sorted Array
Given two sorted integer arrays nums1 and nums2, merge nums2 into nums1 as one sorted array.
138. Copy List with Random Pointer
A linked list of length n is given such that each node contains an additional random pointer, which could point to any node in the list, or null.Construct a deep copy of the list.
1335. Minimum Difficulty of a Job Schedule
You want to schedule a list of jobs in d days. Jobs are dependent (i.e To work on the i-th job, you have to finish all the jobs j where 0 <= j < i).
Palindrome - 125. Valid Palindrome
Given a string s, determine if it is a palindrome, considering only alphanumeric characters and ignoring cases.
DFS&BFS - 51. N-Queens
The n-queens puzzle is the problem of placing n queens on an n_×_n chessboard such that no two queens attack each other.
Dynamic Programming - 322. Coin Change
Coin Change You are given coins of different denominations and a total amount of money amount. Write a function to compute the fewest number of coins that you need to make up that amount. If that amount of money cannot be made up by any combination of the coins, return -1. Example 1: Input: coins = [1, 2, 5], amount = 11 Output: 3 Explanation: 11 = 5 + 5 + 1 Example 2: Input: coins = , amount = 3 Output: -1 Note: You may assume that you have an infinite number of each kind of coin. 思路： ....
Array - 48. Rotate Image
You are given an n x n 2D matrix representing an image. Rotate the image by 90 degrees (clockwise).
73. Set Matrix Zeroes
Given an m x n matrix. If an element is 0, set its entire row and column to 0. Do it in-place.
Array - 56. Merge Intervals
Given a collection of intervals, merge all overlapping intervals.
LinkedList - 23. Merge k Sorted Lists
Merge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity.
LinkedList - 21. Merge Two Sorted Lists
Merge two sorted linked lists and return it as a new list. The new list should be made by splicing together the nodes of the first two lists.