@[Z1660402068](/user/1132451)
用一个数组来储存 $k$ 有没有被使用
```cpp
//#include<bits/stdc++.h>//万能头
#include <iostream>
#include <algorithm>
#include <string.h>
using namespace std;
int s[110],b[111];
int main ()
{
int n,sum=0;
memset(b,1,sizeof(b));//赋值函数,在<string.h>头文件里
cin>>n;
for(int i=1;i<=n;i++)
cin>>s[i];
sort(s+1,s+n+1);
//for(int i=1;i<=n;i++)
//cout<<s[i]<<endl;
for(int i=1;i<=n;i++){
for(int j=i+1;j<=n;j++){
for(int k=1;k<=n;k++){
if(s[i]+s[j]==s[k]&&b[k]){
sum++;
b[k]=0;
//cout<<s[i]<<" "<<s[j]<<" "<<s[k]<<"\n";
}
}
}
}
cout<<sum;
return 0;
}
```
by yekc2010 @ 2024-04-17 22:36:55
@[yekc2010](/user/1127771) 感谢
by Z1660402068 @ 2024-04-18 14:28:27