@[zifan2](/user/957442) 暴力算法不太彳亍，右转题解区
by LonginusMonkey @ 2023-08-11 09:02:30
谢谢
by zifan2 @ 2023-08-11 09:09:46
@[zifan2](/user/957442) 这题暴力肯定要超时，给它改成B+C=A,
然后用map映射把数据存起来算，就简单多了，见AC代码，不长
```
#include<iostream>
#include<map>
using namespace std;
map<long long,long long>a;
long long b[200005];
int main()
{
long long n,c,tot=0;
cin>>n>>c;
for(int i=1;i<=n;i++)
{
int x;
cin>>x;
a[x]++;
b[i]=x-c;
}
for(int i=1;i<=n;i++)
{
tot+=a[b[i]];
}
cout<<tot;
return 0;
}
```
[AC记录](https://www.luogu.com.cn/record/117459450)
by wbhqm @ 2023-08-11 10:47:52
谢谢
by zifan2 @ 2023-08-11 10:52:49