Cod sursa(job #728809)
Utilizator | Tapean Constantin Galax27 | Data | 28 martie 2012 23:31:24 |
---|---|---|---|
Problema | Fractii | Scor | 30 |
Compilator | cpp | Status | done |
Runda | Arhiva de probleme | Marime | 0.43 kb |
#include<stdio.h>
#include<stdlib.h>
int v[1000000];
int main()
{FILE *fo,*fc;
int n=0,i=0,j=0,nr=0;
fo=fopen("fractii.in","r");
fscanf(fo,"%d",&n);
fclose(fo);
for(i=1;i<=n;i++)
v[i]=i;
for(i=2;i<=n;i++)
if(v[i]==i)
for(j=i;j<=n;j+=i)
{v[j]/=i;
v[j]*=(i-1);
}
for(i=1;i<=n;i++)
nr+=v[i];
nr*=2;
fc=fopen("fractii.out","w");
fprintf(fc,"%d",nr-1);
fclose(fc);
return 0;
}