Cod sursa(job #323124)
Utilizator | Data | 10 iunie 2009 20:39:05 | |
---|---|---|---|
Problema | Fractii | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva de probleme | Marime | 0.33 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++)
v[i]=i-1;
for(i=2;i<=n;i++)
{
nr+=v[i];
for(j=2*i;j<=n;j+=i)
v[j]-=v[i];
}
printf("%lld",nr*2+1);
return 0;
}