Cod sursa(job #442632)

Utilizator mayi_rmbunget marius andrei mayi_rm Data 14 aprilie 2010 21:33:05
Problema Fractii Scor 0
Compilator c Status done
Runda Arhiva de probleme Marime 0.3 kb
Raporteaza aceasta sursa 
#include <stdio.h>

int main (){
long long i,j,s,n;
long  v[1000001];


//freopen("ciur.in","r","stdin");
//freopen("ciur.out","w","stdout");
scanf("%lld",&n);
s=0;
for(i=2;i<=n;i++)
	v[i]=i-1;
for(i=2;i<=n;i++){
	s+=v[i];
	for(j=2*i;j<=n;j+=i)
		v[j]-=v[i];
}
s=(s*2)+1;  
printf("%lld",s);
return 0;
}