错误传送门

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
const ll N = 2e5 + 5;

ll a[N];
int main(){
    ll n, c;
    scanf("%lld %lld", &n, &c);
    for(ll i = 1; i <= n; i++) {
        scanf("%lld", &a[i]); 
    }
    ll ans = 0;
    sort(a + 1, a + n + 1);
    for(ll i = 1; i < n; i++) {
        ll h = a[i] + c, t = lower_bound(a + 1, a + n + 1, h) - a;
        if(t > n || a[t] != h) {
            continue;
        }
        while(t <= n && a[t] == h) {
            ans++;
            t++;
        }
    }
    printf("%lld", ans);
    return 0;
}