Cod sursa(job #952748)

Utilizator gabrielinelusGabriel-Robert Inelus gabrielinelus Data 23 mai 2013 21:54:45
Problema Invers modular Scor 60
Compilator cpp Status done
Runda Arhiva educationala Marime 0.6 kb
#include <cstdio>
FILE *f=fopen("inversmodular.in","r");
FILE *g=fopen("inversmodular.out","w");
long long mod;
long long phi(long long N)
{
    int rez=0;
    for(int i=2;i<N;i++)
        if(N%i==0)rez++;
    if(rez==0)
    return N-2;
    return rez;
}
long long invers(long long a,long long N)
{
    long long x1=1,x2=a;
    if(N==1)return a;
    while(N>1)
        if(N%2){x1=(x2*x1)%mod;N--;}
        else {x2=(x2*x2)%mod;N/=2;}
    return (x1*x2)%mod;

}
int main()
{
    long long a,N,put;
    fscanf(f,"%lld%lld",&a,&N);mod=N;
    fprintf(g,"%lld",invers(a,N-2));
    return 0;
}