題目網址:https://www.luogu.org/problem/U75481 (公衆可見)
#include<bits/stdc++.h>
using namespace std;
bool prime(int n){
if (n==1) return 0;
for (int i=2;i*i<=n;i++){
if (n%i==0) return 0;
}
return 1;
} //判斷是否是素數
int main(){
int n,s,j,t;
cin>>n;
for (int i=2;i<=n;i++){
t = i;
s = 0;
j = 2;
while (t!=1){
if (t % j==0){
s++;
t/=j;
} else j++;
}
if (prime(s)) cout<<i<<endl;
}
return 0;
}