```cpp
#include <iostream>
#include <vector>
using namespace std;
int n, k;
vector<int> a;
int cnt = 0;
bool isPrime(int x) {
if (x == 1) return false;
if (x == 2 || x == 3) return true;
for (int i = 2; i * i <= x; i++) {
if (x % i == 0) return false;
}
return true;
}
void dfs(int num, int sum, int remaining) {
if (remaining == 0) {
if (isPrime(sum)) {
cnt++;
}
return;
}
for (int i = num; i < n; i++) {
dfs(i + 1, sum + a[i], remaining - 1);
}
}
int main() {
cin >> n >> k;
a.resize(n);
for (int i = 0; i < n; i++) {
cin >> a[i];
}
dfs(0, 0, k);
cout << cnt;
return 0;
}
```
by CodeAnythingNow @ 2024-05-12 10:45:20
@[__oio__](/user/1112369) @[__oio__](/user/1112369)
```cpp
#include <iostream>
#include <vector>
using namespace std;
int n, k;
vector<int> a;
int cnt = 0;
bool isPrime(int x) {
if (x == 1) return false;
if (x == 2 || x == 3) return true;
for (int i = 2; i * i <= x; i++) {
if (x % i == 0) return false;
}
return true;
}
void dfs(int num, int sum, int remaining) {
if (remaining == 0) {
if (isPrime(sum)) {
cnt++;
}
return;
}
for (int i = num; i < n; i++) {
dfs(i + 1, sum + a[i], remaining - 1);
}
}
int main() {
cin >> n >> k;
a.resize(n);
for (int i = 0; i < n; i++) {
cin >> a[i];
}
dfs(0, 0, k);
cout << cnt;
return 0;
}
```
by CodeAnythingNow @ 2024-05-12 10:46:40
@[songhongjin](/user/1135135) 老师泥哲。。。
by __oio__ @ 2024-05-12 10:47:31
[我](https://www.luogu.com.cn/user/1135135#practice)刚到洛谷
by CodeAnythingNow @ 2024-05-12 10:50:14
我这代码在逻辑上是正确的（doge）
by CodeAnythingNow @ 2024-05-12 10:53:43
```cpp
#include<bits/stdc++.h>
using namespace std;
bool isprime(int n){
if(n<2){
return 0;
}
for(int i=2;i*i<=n;i++){
if(n%i==0){
return 0;
}
}
return 1;
}
int a[105];
int main(){
int n;
cin>>n;
for(int i=1;i<=n;i++){
cin>>a[i];
if(isprime(a[i])){
cout<<a[i]<<" ";
}
}
return 0;
}
```
AC
by E303 @ 2024-05-12 11:10:33
@[E303](/user/1106358) 已关QwQ
by __oio__ @ 2024-05-13 19:46:48
@[E303](/user/1106358) AC个蛋啊！！！
by LYZ0602 @ 2024-06-02 16:01:19
@[LYZ0602](/user/1246191) 扶额苦笑,其实我没看懂（悄咪咪
by __oio__ @ 2024-06-02 19:50:54
@[LYZ0602](/user/1246191)
衮衮衮'!'*10^999999
我都能AC
你怎么不能
by E303 @ 2024-06-02 21:21:45