You are playing the following Flip Game with your friend: Given a string that contains only these two c…

1. 题目 Given a string containing only digits, restore it by returning all possible valid IP address combination…

  Given a pattern and a string str, find if strfollows the same pattern. Here fo…

  Given an integer (signed 32 bits), write a function to check whether it is a power of 4. Example: Given…

  Given a 2D grid, each cell is either a wall 'W', an enemy 'E' or empty '0' (the number zero), return th…

  Nearly every one have used the Multiplication Table. But could you find out the k-th sma…

  We are given two strings, A and B. A shift on A consists of taking string…

题目： Suppose a sorted array is rotated at some pivot unknown to you beforehand. (i.e., 0 1 2 4 5 6 7 …

  Given two integers representing the numerator and denominator of a fraction, return the fraction in str…

  Define S = [s,n] as the string S which consists of n connected strings s. For example, […

Add Two Numbers You are given two linked lists representing two non-negative numbers. The digits are stored in…

  Given two arrays of length m and n with digits 0-9 representing two numbe…