LeetCode—Divide and Conquer--53. Maximum Subarray

问题：https://leetcode.com/problems/maximum-subarray/?tab=Description
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.
求最大的连续子串和。
分析：动态规划问题(DP)。要找最大子串的和，需要遍历数组，不断保存更大的和值，同时在和值小于0的时候舍弃和的值。
C++代码：

class Solution {public:    int maxSubArray(vector<int>& nums) {        int l=nums.size();        int s=0;        int res=nums[0];        for(int i=0;i<l;i++){            if(s<0)            s=0;            s+=nums[i];            res=max(s,res);        }        return res;    }};