需要呢么麻烦吗?
AC
```c
#include<bits/stdc++.h>
using namespace std;
using namespace std;
typedef long long LL;
LL a[200001];
map<LL,LL> m;
int main() {
int n;
LL c;
LL ans=0;
cin >> n >> c;
for(int i=1;i<=n;i++) {
cin >> a[i];
m[a[i]]++;
a[i]-=c;
}
for(int i=1;i<=n;i++) ans+=m[a[i]];
cout << ans << endl;
return 0;
}
```
by timmyliao @ 2024-02-02 12:17:32
@[timmyliao](/user/1095093) 人家是 JAVA 好吗。
by xiaoshumiao @ 2024-02-02 12:33:42
话说 lz 不是 A 了吗。
by xiaoshumiao @ 2024-02-02 12:35:33
@[xiaoshumiao](/user/1008513) sum应该开long的,我AC了
by Kxzzy_n @ 2024-02-03 00:22:30
@[Kxzzy_n](/user/1060961) Yes,P2249你用Java写的MLE了没
by AUST_Ake @ 2024-02-04 14:32:03