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.

如果当前和为负数，再加也没意义，那么从当前sum=a[i]开始，反正不会再差了。。。。

class Solution {
public:
    int maxSubArray(int A[], int n) {
        int res=INT_MIN;
        int sum=0;
        for(int i=0; i<n; i++){
            sum<0? sum=A[i]: sum+=A[i];
            res=max(sum,res);
        }
        return res;
    }
};