IncredibleThings

摘要： Given an array S of n integers, are there elements a, b, c, and d in S such that a + b + c + d = target? Find all unique quadruplets in the array which gives the sum of target. Note: The solution se... 阅读全文

摘要： Given a digit string, return all possible letter combinations that the number could represent. A mapping of digit to letters (just like on the telepho 阅读全文

摘要： Given an array S of n integers, find three integers in S such that the sum is closest to a given number, target. Return the sum of the three integers. You may assume that each input would have exactl... 阅读全文

摘要： 我们可以先固定一个数，然后找另外两个数之和为第一个数的相反数就可以了。 阅读全文

摘要： 这道题是比较常考的题目，求回文子串，一般有两种方法。 第一种方法比较直接，实现起来比较容易理解。基本思路是对于每个子串的中心（可以是一个字符，或者是两个字符的间隙，比如串abc,中心可以是a,b,c,或者是ab的间隙，bc的间隙）往两边同时进行扫描，直到不是回文串为止。假设字符串的长度为n,那么中心 阅读全文

摘要： We are playing the Guess Game. The game is as follows: I pick a number from 1 to n. You have to guess which number I picked. Every time you guess wrong, I'll tell you whether the number is higher o... 阅读全文

摘要： Given two arrays, write a function to compute their intersection. Example: Given nums1 = [1, 2, 2, 1], nums2 = [2, 2], return [2, 2]. Note: Each element in the result should appear as many times as... 阅读全文

摘要： Given two arrays, write a function to compute their intersection. Example: Given nums1 = [1, 2, 2, 1], nums2 = [2, 2], return [2]. Note: Each element in the result must be unique. The result can be... 阅读全文

摘要： Write a function that takes a string as input and reverse only the vowels of a string. Example 1: Given s = "hello", return "holle". Example 2: Given s = "leetcode", return "leotcede". public cla... 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". public class Solution { public String reverseString(String s) { ... 阅读全文