CodeForcesGym 100753K Upside down primes

Upside down primes

Time Limit: 2000ms

Memory Limit: 262144KB

This problem will be judged on CodeForcesGym. Original ID: 100753K
64-bit integer IO format: %I64d      Java class name: (Any)

 

解题：大数素性测试

 #include <bits/stdc++.h>
 using namespace std;
 typedef long long LL;
 LL mul(LL a,LL b,LL mod) {
     if(!a) return ;
     return ((a&)*b%mod + (mul(a>>,b,mod)<<)%mod)%mod;
 }
 LL quickPow(LL a,LL d,LL n){
     LL ret = ;
     while(d){
         if(d&) ret = mul(ret,a,n);
         d >>= ;
         a = mul(a,a,n);
     }
     return ret;
 }
 bool check(LL a,LL d,LL n){
     if(n == a) return true;
     while(~d&) d >>= ;
     LL t = quickPow(a,d,n);
     while(d < n- && t !=  && t != n-){
         t = mul(t,t,n);
         d <<= ;
     }
     return (d&)||t == n-;
 }
 bool isP(LL n){
     if(n == ) return true;
     if(n <  ||  == (n&)) return false;
     static int p[] = {,,,,,,};
     for(int i = ; i < ; ++i)
         if(!check(p[i],n-,n)) return false;
     return true;
 }

 bool trans(LL x){
     char str[];
     sprintf(str,"%I64d",x);
     for(int i = ; str[i]; ++i)
         if(str[i] == '' || str[i] == '' || str[i] == '') return false;
     reverse(str,str + strlen(str));
     for(int i = ; str[i]; ++i)
         if(str[i] == '') str[i] = '';
         else if(str[i] == '') str[i] = '';
     sscanf(str,"%I64d",&x);
     return isP(x);
 }
 int main(){
     LL x;
     while(~scanf("%I64d",&x)){
         if(isP(x) && trans(x)) puts("yes");
         else puts("no");
     }
     return  ;
 }