1702 素数判定 2[[一中数论随堂练]

#include<cstdio>
#include<iostream>
using namespace std;
#define ll long long
ll n;
int prime[]={2,3,5,7,11,13,17,19,23,29};
ll cheng(ll a,ll b){/*慢速乘法*/  
    ll ans=0;
    for(ll i=a;i;i>>=1){
        if(i&1) ans=(ans+b)%n;
        b=(b+b)%n;
    }
    return ans%n;
}
ll mull(ll a,ll b){/*快速幂 */ 
    ll ans=1;
    for(ll i=a;i;i>>=1){
        if(i&1) ans=cheng(ans,b)%n;
        b=cheng(b,b)%n;
    }
    return ans%n;
}
bool check(){
    if(n==2) return 1;
    if(n<2||n&1==0) return 0;
    for(int i=0;i<10;i++){/*费马定理+验证法*/
        if(mull(n-1,prime[i])!=1) return 0;
    }
    return 1;
}
int main(){
    cin>>n;
    if(check()) puts("Yes");
    else puts("No");
    return 0;
}