动态规划----最大子序和

题目：

Maximum Subarray
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.

标签是动态规划但是没看出来哪里是……..感觉是很简单的一题……

c++代码（O(N)解法）

class Solution {
public:
    int maxSubArray(vector<int>& nums) {
        int sum = nums[0];
        int cur_sum = 0;

        for (size_t i = 0; i < nums.size(); ++i) {
            cur_sum += nums[i];
            if (cur_sum > sum) sum = cur_sum;
            if (cur_sum < 0 ) cur_sum = 0;
        }

        return sum;
    }
};