超时了两个样例，我用的是双指针啊

#include <bits/stdc++.h>
using namespace std;
const int N = 2e5 + 5;
int a[N];
int n;
int main() {
    int c;
    long long cnt = 0;
    cin >> n >> c;
    for (int i = 0; i < n; i++) {
        cin >> a[i];
    }
    sort(a, a + n);
    int j = 0;
    for (int i = 0; i < n; i++) {
        j = i + 1;
        while (j < n && a[j] - a[i] < c) 
            j++;
        int k = j;
        while (k < n && a[k] - a[i] == c) {
            cnt++;
            k++;
        }
    }
    printf("%lld\n", cnt);
    return 0;
}