Cod sursa(job #255524)
Utilizator | Data | 9 februarie 2009 21:58:13 | |
---|---|---|---|
Problema | Fractii | Scor | 0 |
Compilator | cpp | Status | done |
Runda | Arhiva de probleme | Marime | 0.38 kb |
#include<fstream.h>
int cmmdc(int x,int y)
{
if(!y)
return x;
return cmmdc(y,x%y);
}
int main()
{
ifstream fin("fractii.in");
ofstream fout("fractii.out");
int n,i,j,s;
fin>>n;
s=4*n-5;
for(i=2;i<=n-2;i+=2)
for(j=i+3;j<=n;j+=2)
s+=2;
for(i=3;i<=n-2;i+=2)
for(j=i+2;j<=n;j++)
if(cmmdc(i,j)!=1)
s+=2;
fout<<s;
return 0;
}