解法：

统计个数用数组做桶即可

#include<iostream>
#include<vector>
#include<algorithm>
using namespace std;
#define endl '\n'
int main()
{
	vector<int> tong(301, 0);
	int n, m, a;
	cin >> n >> m;
	while (n--) {
		cin >> a;
		tong[a]++;
	}
	long long sum = 0;
	for (int i = 300; ~i; i--) {
		sum += tong[i];
		if (sum >= m) {
			cout << i << endl;
			return 0;
		}
	}
	
	return 0;
}