Kth Smallest Element in a Sorted Matrix.cpp

// Runtime: 108 ms, faster than 53.91% of C++ online submissions for Kth Smallest Element in a Sorted Matrix.
// Memory Usage: 14.6 MB, less than 39.25% of C++ online submissions for Kth Smallest Element in a Sorted Matrix.

class Solution {
public:
	int kthSmallest(vector<vector<int>>& matrix, int k) {
		int m = matrix.size();
		if (m == 0){
            return 0;
        }
		int n = matrix[0].size();

		if (n == 0){
            return 0;
        }
		priority_queue<int> pq;
		for (int i=0; i<m; i++){
			for (int j=0; j<n; j++){
				pq.push(matrix[i][j]);
				if (pq.size() > k){
					pq.pop();
                }
			}
        }
		return pq.top();
	}
};