Leetcode-53. Maximum Subarray

题目：

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.

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AC代码：

class Solution {
public:
	int maxSubArray(vector& nums) {
		int size = nums.size();
		if (size == 0)return 0;
		vectorsum(size,0);
		int maxsum = INT_MIN;
		for (int i = 0; i < size;i++){
			sum[i] = i>0?max(sum[i-1]+nums[i],nums[i]):nums[i];
			if (sum[i]>maxsum)maxsum = sum[i];
		}
		return maxsum;
	}
};

解析：

代码中sum[i]是以nums[i]为最后一个元素的最大连续子串和。如果sum[i-1]加上nums[i]的值没有num[i]大，则sum[i]=nums[i]，否则sum[i]=sum[i-1]+

nums[i]。