[LeetCode]Maximum Subarray

class Solution {
//OJ suggest to solve this problem using D&C, but its time complexity is O(nlogn), right?
//So I choose the O(n) version to implement
public:
	int maxSubArray(int A[], int n) {
		// Start typing your C/C++ solution below
		// DO NOT write int main() function
		if(0 == n) return 0;
		int ans = A[0];
		int local = 0;
		for (int i = 0; i < n; ++i)
		{
			local = local > 0 ? local+A[i] : A[i];
			ans = max(local, ans);
		}
		return ans;
	}
};

second time

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 curSum = A[0];
        int maxSum = curSum;
        for(int i = 1; i < n; ++i)
        {
            if(curSum+A[i] > A[i]) curSum = curSum+A[i];
            else curSum = A[i];
            maxSum = max(maxSum, curSum);
        }
        
        return maxSum;    
    }
};