53. 最大子序列和Maximum Subarray

题目名称

Maximum Subarray

题目描述

Given an integer array nums, find the subarray（连续的） which has the largest sum and return its sum.

Example 1:

Input: nums = [-2,1,-3,4,-1,2,1,-5,4]
Output: 6
Explanation: [4,-1,2,1] has the largest sum = 6.
Example 2:

Input: nums = [1]
Output: 1
Example 3:

Input: nums = [5,4,-1,7,8]
Output: 23

Constraints:

1 <= nums.length <= 105
-104 <= nums[i] <= 104

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.

思路

1，暴力法（O(n*n)）
2, 动态规划
3，分治法（递归）

代码1

// dp
class Solution {
public:
    int maxSubArray(vector& nums) {
        int dp;
        dp = nums[0];
        int max = dp;
        int tmp;
        for(int i=1; imax){
                max = dp;
            }
        }
        return max;
        
    }
};

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24

代码2

// dq

1
2