Cod sursa(job #1900528)

Utilizator RaduGiucleaGiuclea Radu RaduGiuclea Data 3 martie 2017 14:13:45
Problema Invers modular Scor 10
Compilator cpp Status done
Runda Arhiva educationala Marime 0.72 kb
#include <cstdio>
using namespace std;
int p(int a,int put,int mod)
{
    int pow=1;
    while(put)
    {
        if(put%2)
        {
            put--;
            pow*=a;
            pow%=mod;
        }
        a*=a;
        a%=mod;
        put/=2;
    }
    return pow;
}
int main()
{
    freopen("inversmodular.in","r",stdin);
    freopen("inversmodular.out","w",stdout);
    int n,a,i,put,cn;
    scanf("%d%d",&a,&n);
    put=n-1;
    cn=n;
    for(i=2;i*i<=n;i++)
        if(n%i==0)
        {
            put-=put/i;
            while(n%i==0)
                n/=i;
        }
    if(n>1&&put>n)
        put-=put/n;
    n=cn;
    put--;
    a%=n;
    printf("%d",p(a,put,n));
    return 0;
}