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.
Follow up:
If you have figured out the O(n) solution, try coding another solution using the divide and conquer approach, which is more subtle.
题目链接：https://leetcode.com/problems/maximum-subarray/
思路：首先用sum对数列求和，如果求和sum<0,小于0，肯定不可能是最大子序列的组成部分，所以重置为0。对于res，用sum+nums[i],来更新res
class Solution {
public:
int maxSubArray(vector<int> &nums) {
if(nums.size()<0)
return 0;
int res=nums[0],sum=0;
int len=nums.size();
for(int i=0;i<len;i++)
{
sum+=nums[i];
res=max(res,sum);
sum=max(sum,0);
}
return res;
}
};