Subarray Sum 原题链接:http://lintcode.com/zh-cn/problem/subarray-sum/# Given an integer array, find a subarray where the sum of numbers is zero. Your code should return the index of the first number and the index of the last number. 样例 Given [-3, 1, 2, -…

Subarray Sum Given an integer array, find a subarray where the sum of numbers is zero. Your code should return the index of the first number and the index of the last number. Example Given [-3, 1, 2, -3, 4], return [0, 2] or [1, 3]. 用hashmap来存从nums[0…

Given an integer array, find a subarray with sum closest to zero. Return the indexes of the first number and last number. Have you met this question in a real interview? Yes Example Given [-3, 1, 1, -3, 5], return [0, 2], [1, 3], [1, 1], [2, 2] or [0…

For this problem we need to learn a new trick that if your start sum up all elements in an array. When you start from a to b to sum up all elements, if the result is zero, and also the summation of all elements from index a to c ( c<=b ) is zero. The…

Sliding window doesn't work. So it is a typical partial_sum base solution. As below. However if you use a balanced binary search tree, you can get O(nlgn) - like std::set<int> class Solution { public: /** * @param A an integer array * @param start a…

LintCode 402: Continuous Subarray Sum 题目描述 给定一个整数数组,请找出一个连续子数组,使得该子数组的和最大.输出答案时,请分别返回第一个数字和最后一个数字的下标.(如果两个相同的答案,请返回其中任意一个) 样例 给定[-3, 1, 3, -3, 4], 返回[1,4]. Thu Feb 23 2017 思路 本题有很多解法,最巧妙的解法就是一遍扫描记忆的方法了,时间复杂度为\(O(n)\). 用一个变量记录连续累加的和,当和为负数时,变量清零,从下一个数字…

Given an array of n positive integers and a positive integer s, find the minimal length of a subarray of which the sum ≥ s. If there isn't one, return -1 instead. Have you met this question in a real interview?     Example Given the array [2,3,1,2,4,…

Given an integer array, find a continuous rotate subarray where the sum of numbers is the biggest. Your code should return the index of the first number and the index of the last number. (If their are duplicate answer, return anyone. The answer can b…

Continuous Subarray Sum II   Given an circular integer array (the next element of the last element is the first element), find a continuous subarray in it, where the sum of numbers is the biggest. Your code should return the index of the first number…

整体上3个题都是求subarray,都是同一个思想,通过累加,然后判断和目标k值之间的关系,然后查看之前子数组的累加和. map的存储:560题是存储的当前的累加和与个数 561题是存储的当前累加和的余数与第一次出现这个余数的位置 325题存储的是当前累加和与第一次出现这个和的位置 其实561与325都是求的最长长度,那就一定要存储的是第一次出现满足要求的位置,中间可能还出现这种满足要求的情况,但都不能进行存储 560. Subarray Sum Equals K 求和为k的连续子数组的个数 h…