连续子数组的最大和

class Solution {
public:
    int maxSubArray(vector<int>& nums) {
        int n=nums.size(),res=-0x3f3f3f3f;
        for (int i = 0; i < n;)//枚举以i为起点的区间
        {
            int j=i,sum=0;
            while(j<n)
            {
                sum+=nums[j];
                res=max(res,sum);
                if(sum<=0)  break;
                j++;
            }
            i=j+1;
        }
        return res;
    }
};