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.

class Solution {
public:
    int maxSubArray(vector<int>& nums) {
    int n=nums.size();
    int res=nums[0];
    int k=nums[0],i;
    for(i=1;i<n;i++)
    {
        //前面的数值不能是负的
        k=(k>0)?(k+nums[i]):nums[i];
        res=max(k,res);
    }
    return res;
    }
};