Cod sursa(job #323122)
Utilizator | Chilivercu Cristian Anonymous1010 | Data | 10 iunie 2009 20:35:13 |
---|---|---|---|
Problema | Fractii | Scor | 30 |
Compilator | cpp | Status | done |
Runda | Arhiva de probleme | Marime | 0.4 kb |
#include<stdio.h>
int n,i,j,v[1000000];
long long nr,p1,p2;
int main()
{
freopen("fractii.in","r",stdin);
freopen("fractii.out","w",stdout);
scanf("%d",&n);
for(i=2;i<=n;i++)
{
p1=i;
p2=1;
for(j=2;j<=i;j++)
if(!v[j]&&i%j==0)
{
p1*=(j-1);
p2*=j;
}
nr+=(p1/p2);
for(j=2*i;j<=n;j+=i)
v[j]=1;
}
printf("%lld",nr*2+1);
return 0;
}