2，3WA，4RE为啥...另外我这个时间复杂度是多少？

#include<iostream>
#include<algorithm>
using namespace std;
int main()
{
	long n, t, a[100005];
	long x, y, flag = 0, cont = 0;
	cin >> n >> t;
	for (int i = 0; i < n; i++)
		cin >> a[i];
		
	sort(a, a + n);
	for (int i = 0; i < n; i++)
	{
		if (a[i] <= t)
			flag = i;
	}
	x = 0;
	y = n - 1;
	while (y >= flag && x < y)
	{
		if (a[y] - a[x] > t)
		{
			x++;
		}
		if (a[y] - a[x] < t)
		{
			y--;
			x = 0;
		}
		if (a[y] - a[x] == t)
		{
			cont++;
			x++;
		}
	}
	cout << cont;
	return 0;
}