Largest Perimeter Triangle — C++

// Time:  O(nlogn)
// Space: O(1)

class Solution {
public:
    int largestPerimeter(vector<int>& A) {
        sort(A.begin(), A.end());
        for (int i = A.size() - 3; i >= 0; --i) {
            if (A[i] + A[i + 1] > A[i + 2]) {
                return A[i] + A[i + 1] + A[i + 2];
            }
        }
        return 0;
    }
};