LeetCode C++ 53. Maximum Subarray【動態規劃】簡單

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.

題意：求出最大子序列和。

思路：做過的一個題目了，可以用動態規劃。

代碼：

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