Cod sursa(job #414818)

Utilizator Catah15Catalin Haidau Catah15 Data 10 martie 2010 16:23:12
Problema Fractii Scor 100
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.32 kb
Raporteaza aceasta sursa 
#include <iostream.h>
#include <fstream.h>
long long n,x[1000005],i,j,S=0;
int main()
{
ifstream f("fractii.in");
ofstream g("fractii.out");
f>>n;
for(i=2;i<=n;i++)
	x[i]=i-1;
for(i=2;i<=n;i++)
	{
	S=S+x[i];
	for(j=i*2;j<=n;j=j+i)
		x[j]=x[j]-x[i];
	}
S=S*2+1;
g<<S;
f.close();
g.close();
return 0;
}