53. 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) {
        if(nums.size()==0) 
        return 0;
        else if(nums.size()==1)
        return nums[0];


        int sum = nums[0];
        int re = sum;


        for(int i = 1; i < nums.size(); ++i)
        {
            if(sum <= 0)
            sum = nums[i];
            else
            sum += nums[i];
            re = max(sum, re);
        }
        return re;
    }
};