[LeetCode] 050: Maximum Subarray_综合

[Problem]

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.

More practice:

If you have figured out the O(n) solution, try coding another solution using the divide and conquer approach, which is more subtle.

[Solution]

class Solution {
   
public:
    int maxSubArray(int A[], int n) {
   
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        if(n <= 0)return 0;
        int sum[n], res = A[0];
        for(int i = 0; i < n; ++i){
   
            if(i == 0){
   
                sum[i] = A[i];
            }
            else{
   
                sum[i] = max(sum[i-1] + A[i], A[i]);
            }
            res = max(res, sum[i]);
        }
        return res;
    }
};