题解 | #寻找第K大#

import java.util.*;

public class Solution {
    public int findKth(int[] a, int n, int k) {
        // write code here
        if (a == null || n < 1 || k < 1 || n < k) {
            return -1;
        }
        PriorityQueue<Integer> pq = new PriorityQueue<>();
        for (int i = 0; i < n; i++) {
            if (i < k) {
                pq.offer(a[i]);
            } else if (pq.peek() < a[i]) {
                pq.poll();
                pq.offer(a[i]);
            }
        }
        return pq.poll();
    }
}