Cod sursa(job #1751893)
| Utilizator | Data | 2 septembrie 2016 11:58:18 | |
|---|---|---|---|
| Problema | Invers modular | Scor | 50 |
| Compilator | cpp | Status | done |
| Runda | Arhiva educationala | Marime | 0.62 kb |
#include <stdio.h>
#define ll long long
using namespace std;
ll a,n,p,sol=1;
ll prim(ll nr)
{
ll prime=nr;
for(ll i=2;i*i<=nr;i++)
if(nr%i==0)
{
while(nr%i==0)nr/=i;
prime=prime/i*(i-1);
}
if(nr!=1)prime=prime/nr*(nr-1);
return prime;
}
int main()
{
freopen("inversmodular.in","r",stdin);
freopen("inversmodular.out","w",stdout);
scanf("%lld%lld",&a,&n);
p=prim(n)-1;
for(ll i=0;(1<<i)<=p;i++)
{
if(((1<<i)&p)>0)
sol=(sol*a)%n;
a=(a*a)%n;
}
printf("%lld",sol);
}
