UVA 10006 Carmichael Numbers

#include <map>#include <set>#include <list>#include <cmath>#include<cctype>#include <ctime>#include <deque>#include <stack>#include <queue>#include <cstdio>#include <string>#include <vector>#include<climits>#include <cstdlib>#include <cstring>#include <iostream>#include <algorithm>#define LL long long#define PI 3.1415926535897932626using namespace std;int gcd(int a, int b) {return a % b == 0 ? b : gcd(b, a % b);}bool prime[66000];LL N;void init(){    for (int i=0;i<66000;i++) prime[i]=true;    prime[0]=prime[1]=false;    for (int i=2;i*i<66000;i++)        if (prime[i])        for (int j=i+i;j<66000;j+=i)         prime[j]=false;}LL pow_mod(LL a,LL b,LL m){    LL ans=1;    a%=m;    while (b)    {        if (b&1) ans=(ans*a)%m;        a=(a*a)%m;        b>>=1;    }    return ans;}int main(){    init();    while (scanf("%lld",&N)!=EOF)    {        if (N==0) break;        if (prime[N]) {printf("%lld is normal.\n",N);continue;}        bool flag=false;        for (LL i=2;i<N;i++)            if (pow_mod(i,N,N)!=i)        {            flag=true;            break;        }        if (flag) printf("%lld is normal.\n",N);        else printf("The number %lld is a Carmichael number.\n",N);    }    return 0;}