改了一次后32分
```cpp
#include<bits/stdc++.h>
using namespace std;
int n,js=0;
int a[21];
bool pd(int x)
{
for(int i=2;i*i<=n;i++)
{
if(n%i==0)
{
return 0;
}
}
return 1;
}
void dfs(int zx,int x,int zs)
{
if(x==0)
{
if(pd(zs))
{
js++;
}
return;
}
for(int i=zx;i<=n-x+1;i++)
{
zs+=a[i];
dfs(i+1,x-1,zs);
zs-=a[i];
}
}
int main()
{
int k;
cin>>n>>k;
for(int i=1;i<=n;i++)
{
cin>>a[i];
}
sort(a+1,a+n+1);
dfs(1,k,0);
cout<<js;
return 0;
}
``````
by ycy1124 @ 2024-02-20 09:06:08
@[ycy1124](/user/1199534) hack:
~~~
5 4
1 2 3 4 5
~~~
怎么都不可能是120啊
by DFs_YYDS @ 2024-02-20 09:15:02
本人眼瞎，将pd函数x写成n,改了之后AC
by ycy1124 @ 2024-02-20 09:16:21
@[DFs_YYDS](/user/1119406)
谢谢，本人已关注
by ycy1124 @ 2024-02-20 09:24:53