P1102数对

看题解里优雅的暴力，tql，%%%

//自己写了一遍
#include 
#define int long long
#define _rep(i,a,b) for( int i=(a); i<=(b); ++i)
#define _down(i,a,b) for( int i=(a); i>=(b); --i)
#define IOS ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
using namespace std;
const int mx = 1e6 + 9;
int n, x, ans, a[mx];
void solve() {
    cin >> n >> x;
    _rep(i, 1, n) cin >> a[i];
    sort(a + 1, a + 1 + n);
    ans = 0;
    _rep(i, 1, n) {
        ans += (upper_bound(a + 1, a + 1 + n, a[i] + x) - a) - (lower_bound(a + 1, a + 1 + n, a[i] + x) - a);
    }
    cout << ans;
}

signed main() {
    IOS;
    solve();
    //test();
    return 0;
}