Dynamic Programming There is a nice introduction to the DP algorithm in this Wikipedia article. The idea is to maintain a running maximum smax and a current summation sum. When we visit each num in nums, addnum to sum, then update smax if necessary o…

Maximum Subarray Sum 题意 给你一个大小为N的数组和另外一个整数M.你的目标是找到每个子数组的和对M取余数的最大值.子数组是指原数组的任意连续元素的子集. 分析 参考 求出前缀和,问题变成了O(n*n)复杂度的问题,但是仍然不能解决问题. 设prefix为前缀和,设i < j,一般都是通过算sum = prefix[j] - prefix[i]求和的最大值,但是本题中有取模,要求sum最大. 第一种情况:如果prefix[j] > prefix[i],sum < pr…

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…

Maximum Subarray Find the contiguous subarray within an array (containing at least one number) which has the largest sum. For example, given the array [−2,1,−3,4,−1,2,1,−5,4],the contiguous subarray [4,−1,2,1] has the largest sum = 6. More practice:…

Maximum Subarray Find the contiguous subarray within an array (containing at least one number) which has the largest sum. For example, given the array [−2,1,−3,4,−1,2,1,−5,4],the contiguous subarray [4,−1,2,1] has the largest sum = 6. SOLUTION 1: 采用滑…

Maximum Subarray: Find the contiguous subarray within an array (containing at least one number) which has the largest sum. For example, given the array [-2,1,-3,4,-1,2,1,-5,4], the contiguous subarray [4,-1,2,1] has the largest sum = 6. 这是动态规划的一道较简单的…

原题链接在这里:https://leetcode.com/problems/continuous-subarray-sum/description/ 题目: Given a list of non-negative numbers and a target integer k, write a function to check if the array has a continuous subarray of size at least 2 that sums up to the multip…

Given an array of integers and an integer k, you need to find the total number of continuous subarrays whose sum equals to k. Example 1: Input:nums = [1,1,1], k = 2 Output: 2 Note: The length of the array is in range [1, 20,000]. The range of numbers…

Given an array of integers and an integer k, you need to find the total number of continuous subarrays whose sum equals to k. Example 1: Input:nums = [1,1,1], k = 2 Output: 2 Note: The length of the array is in range [1, 20,000]. The range of numbers…

题目如下: Given an array of integers, return the maximum sum for a non-empty subarray (contiguous elements) with at most one element deletion. In other words, you want to choose a subarray and optionally delete one element from it so that there is still…