运行时半天没反应
(我不求AC)
#include<bits/stdc++.h>
using namespace std;
int n;
int x;
int a[200005];
int ans = 0;
int f(int i, int j) {
if (a[i] - a[j] == x) ans ++;
if (j == 1 && i == n) return ans;
if (i == n) f(1, j --);
f(i ++, j);
}
int main() {
cin >> n >> x;
for (int i = 1; i <= n; i ++) cin >> a[i];
cout << f (1, n) << endl;
return 0;
}