https://www.luogu.org/recordnew/show/18271600
by rfsfreffr @ 2019-04-16 18:52:47
@[濤鐵窮氣](/space/show?uid=133813) 复制错了
~~~
#include<bits/stdc++.h>
using namespace std;
int n,m,a[21],ans;
int p(int x) {
if(x==2) return 1;
if(x==1) return 0;
if(x%2==0) return 0;
for(int i=3; i<=sqrt(x); i+=2) {
if(x%i==0) return 0;
}
return 1;
}
void dfs(int i,int j,int sum) {
if(j>m) {
if(p(sum)) ans++;
return ;
}
if(i>n) return ;
————————
————————
}
int main() {
cin>>n>>m;
for(int i=1; i<=n; i++) cin>>a[i];
dfs(1,1,0);
cout<<ans;
}
~~~
by rfsfreffr @ 2019-04-16 18:53:48