摘要：You are given an integer array which contains positive integers, zero and negetive integerscount how many consecutive sequences in this array make a sum of 0.exmapleint[] a = {4, -1, 2, 1, -2, -1, 5, ... 阅读全文

摘要：Given two sorted array in non-descending order, each contains positive integersThe distance is define as followingpick up a number from each array, compute their differencereturn the shortest distance... 阅读全文

摘要：Given a sorted array in non-descending order, the element type can be positive integer or char, return the length of the longest consecutive segmentsExample, Input:"1223334556", output 3Input: "abccde... 阅读全文

摘要：The Longest Common Subsequence problemGive two strings a and b. return the length of the longest common subsequence of them.Note: characters in subsequence needn’t to be consecutive, but in subs... 阅读全文

摘要：Given an array a contains distinct positive integers, count how many combinations of integers in a add up to exactly sumFor example, given int[] a = {... 阅读全文

摘要：消化一个算法最重要的是理解他的思想，而不是急于搞定代码，写文章重要的是阐明道理，而不是简单的粘贴代码，这篇文章需要详细的分析！符号三角形问题是经典的回溯问题，下图是一个符号三角形+ + - ++ - - - + -这个三角形的组成规则是，只能由+和-组成，并且两个相同符号的下面是+，两个不同符号下面是-，设符号三角形第一行有n个符号，对于给定的n，计算有多少种不同的符号三角形，使得+和-的个数相等。例如，当n=4时，共有如下六种符号三角形满足条件+ + - ++ - - - + -+ + - -+ - + - - ++ - + +- - + + - -+ - + -- - - + + +- + 阅读全文