根据题目的定义来做，考quick_mod的应用，比较水
1 #include <cstdio> 2 #include <cstring> 3 #include <iostream> 4 #include <stack> 5 #include <queue> 6 #include <map> 7 #include <algorithm> 8 #include <vector> 9 #include <cmath> 10 11 using namespace std; 12 13 const int maxn = 1000005; 14 15 typedef long long LL; 16 17 vector<int>G[maxn]; 18 19 bool prim(LL n) 20 { 21 int t = (int)sqrt(n)+1; 22 if( n == 2 || n == 1) return 1; 23 LL i; 24 for(i=2;i<=t;i++){ 25 if(n%i == 0){ 26 return 0; 27 break; 28 } 29 } 30 return 1; 31 } 32 33 LL quick_mod(LL a,LL b,LL m) 34 { 35 LL ans = 1; 36 while(b){ 37 if(b&1){ 38 ans = (ans*a)%m; 39 } 40 b>>=1; 41 a = a*a%m; 42 } 43 return ans; 44 } 45 46 int main() 47 { 48 LL a,n,p,b; 49 while(cin>>p>>a&&(a+p)){ 50 if(prim(p)) puts("no"); 51 else{ 52 LL ans = 1; 53 ans = quick_mod(a,p,p); 54 if(ans == a) puts("yes"); 55 else puts("no"); 56 } 57 } 58 59 60 return 0; 61 }