Leetcode:Maximum Subarray

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.

分析：這道題是到很經典的題，關鍵點是要明白sum爲負數的連續subarray對可能的最大值沒有幫助（除該連續subarray的sum爲largest sum外）。因此很簡單的，若是sum小於0，咱們便置sum爲0。代碼以下：

class Solution {
public:
    int maxSubArray(int A[], int n) {
        int result = INT_MIN;
        int sum = 0;
        for(int i = 0; i < n; i++){
            sum += A[i];
            result = max(result, sum);
            if(sum < 0) sum = 0;
        }
        
        return result;
    }
};