摘要：Given two strings s and t, determine if they are isomorphic. Two strings are isomorphic if the characters in s can be replaced to get t. All occurrenc 阅读全文

摘要：Given a sorted array of integers, find the starting and ending position of a given target value. Your algorithm's runtime complexity must be in the or 阅读全文

摘要：Given a string s consists of upper/lower-case alphabets and empty space characters ' ', return the length of last word in the string. If the last word 阅读全文

摘要：Write a function to find the longest common prefix string amongst an array of strings. 大意就是，写一个函数可以找到一个数组字符串中的最长前缀。 分析： 最长前缀的最大值为数组字符串中长度最短的字符，由最短字符串由 阅读全文

摘要：Implement the following operations of a stack using queues. push(x) -- Push element x onto stack. pop() -- Removes the element on top of the stack. to 阅读全文

摘要：Given a string containing only digits, restore it by returning all possible valid IP address combinations. For example:Given "25525511135", return ["2 阅读全文

摘要：Write a function that takes a string as input and returns the string reversed. Example:Given s = "hello", return "olleh". 题目大意就是给一个字符串，得到倒序字符串 corner 阅读全文