@[yi18600361898](/user/1267066) @[yi18600361898](/user/1267066) ~~求关注இ௰இ~~
```cpp
#include<iostream>
#include<cstdio>
using namespace std;
const int M=20005;
int t[M],g[M];
int n,a[105],ans,maxn;
int main(){
cin>>n;
for (int i=1;i<=n;i++){
cin>>a[i];
g[a[i]]=1;
}
for (int i=1;i<n;i++){
for (int j=i+1;j<=n;j++){
t[a[i]+a[j]]++;
maxn=max(maxn,a[i]+a[j]);
}
}
for (int i=1;i<=maxn;i++){
if (t[i]>0&&g[i]) ans++;
}
cout<<ans<<endl;
return 0;
}
```
by quxiangyu @ 2024-02-28 22:20:34
没看懂
by yi18600361898 @ 2024-02-29 12:18:26
@[yi18600361898](/user/1267066) 其实就是加个去重部分,一个数如果等于另外两个数之和,只记录一次,比如[1,2,3,4,5,6]这个集合,1+4等于5,2+3也等于5,但5这个数只记录一次
by yahuac @ 2024-03-31 21:44:16
@[yahuac](/user/997832)
啊,我懂了。
~~但我不会~~
by yi18600361898 @ 2024-04-01 17:29:42