Given an m x n matrix. If an element is 0, set its entire row and column to 0. Do it in-place.

给定一个链表，其中奇数位是升序的，偶数位是降序的，实现链表的排序。

Return True if the path crosses itself at any point, that is, if at any time you are on a location you've previously visited. Return False otherwise.

Given a non-empty string s, you may delete at most one character. Judge whether you can make it a palindrome.

Given an absolute path for a file (Unix-style), simplify it. Or in other words, convert it to the canonical path.

Given two binary strings, return their sum (also a binary string).

Implement pow(x, n), which calculates x raised to the power n (xn).

Given an input string (s) and a pattern (p), implement wildcard pattern matching with support for '?' and '*'.

Write a program to solve a Sudoku puzzle by filling the empty cells.

Determine if a 9x9 Sudoku board is valid.

Given a set of non-overlapping intervals, insert a new interval into the intervals (merge if necessary).

Given a n x n matrix where each of the rows and columns are sorted in ascending order, find the kth smallest element in the matrix.

Given a positive integer n, generate a square matrix filled with elements from 1 to n2 in spiral order.

Given a matrix of m x n elements (m rows, n columns), return all elements of the matrix in spiral order.

Given a non-empty, singly linked list with head node head, return a middle node of linked list.

You are given an n x n 2D matrix representing an image. Rotate the image by 90 degrees (clockwise).

Given two non-negative integers num1 and num2 represented as strings, return the product of num1 and num2, also represented as a string.

Given an array of integers nums sorted in ascending order, find the starting and ending position of a given target value.

Implement next permutation, which rearranges numbers into the lexicographically next greater permutation of numbers.

8.String to Integer (atoi) Implement atoi which converts a string to an integer. The function first discards as many whitespace characters as necessary until the first non-whitespace character is found. Then, starting from this character, takes an optional initial plus or minus sign followed by as many numerical digits as possible, and interprets them as a numerical value. The string can contain additional characters after those that form the integral number, which are ignored and have no effect....