Cod sursa(job #578420)
Utilizator | Data | 11 aprilie 2011 11:52:26 | |
---|---|---|---|
Problema | Invers modular | Scor | 50 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.51 kb |
#include <cstdio>
using namespace std;
FILE *fin=freopen("inversmodular.in","r",stdin);
FILE *fout=freopen("inversmodular.out","w",stdout);
int a,n;
void inv(int a, int n, long long &x, long long &y)
{
if(!n)
x=1,y=0;
else
{
inv(n,a%n,x,y);
long long aux=x;
x=y;
y=aux-(a/n)*y;
}
}
int main()
{
scanf("%d %d",&a,&n);
long long x,y;
inv(a,n,x,y);
if(x<=0)
x=n+n%x;
printf("%lld\n",x);
return 0;
}