第2、3个点WA，别的都AC了。 不知道哪里有问题，求助，谢谢！

#include<iostream>
#include<algorithm>

using namespace std;
bool compare(int a, int b)
{
	return a > b;
}
int main()
{
	int Stu[9001] = { 0 }, a, b, c, i, j, n, m, d, cou = 0;
	cin >> n >> m;
	c = (int)(m * 1.5);
	for (i = 0; i < n; i++)
	{
		cin >> a >> b;
		Stu[i] = 10000 * b + 9999 - a;
	}
	sort(Stu, Stu + n,compare);
	i = 0;
	while (Stu[i] / 10000 >= Stu[c] / 10000) {
		cou++;
		i++;
	}
	cout << Stu[c] / 10000 << " " << cou << endl;
	for (i = 0; i < cou; i++)
		cout << 9999 - Stu[i] % 10000 << " " << Stu[i] / 10000 << endl;
	return 0;
}