【LeetCode】53. Maximum Subarray

53. Maximum Subarray

Easy

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.

class Solution {
public:
    int maxSubArray(vector<int>& nums) {
        int max=nums[0];
        for(int i=1;i<nums.size();i++){
            nums[i]=nums[i-1]>0?nums[i]+nums[i-1]:nums[i];//在原数组上记录截至该元素最大的字段和，取决于之前的是否>=0
            if(nums[i]>max) max=nums[i];
        }
        return max;
    }
};