Given an integer array nums, find the contiguous subarray (containing at least one number) which has the largest sum and return its sum.

Example:

Input: [-2,1,-3,4,-1,2,1,-5,4],
Output: 6
Explanation: [4,-1,2,1] has the largest sum = 6.
Follow up:

If you have figured out the O(n) solution, try coding another solution using the divide and conquer approach, which is more subtle.

来源：力扣（LeetCode）
链接：https://leetcode-cn.com/problems/maximum-subarray
著作权归领扣网络所有。商业转载请联系官方授权，非商业转载请注明出处。

这道题像极了，数据结构里陈越老师讲的链表例题

实时更新就行了。。。（我懂了这道题，别的题稍微变变就不会。。。）

class Solution {
public:
    int maxSubArray(vector<int>& nums) {
        int max=nums[0],sum=nums[0];
        for(int i=1;i<nums.size();i++){
            if(sum<0)sum=0;
            sum+=nums[i];
            if(sum>=max) max=sum;
        }
        return max;
    }
};