Cod sursa(job #490798)

Utilizator chrissBota Cristian chriss Data 7 octombrie 2010 22:53:35
Problema Fractii Scor 0
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.33 kb
Raporteaza aceasta sursa 
#include <stdio.h>

int x[1000010],n,i,j,s=0;

int main()
{
    scanf("%d",&n);
    for(i=2; i<=n; ++i)
    {
        if(x[i]==0)
        {
			s+=i-1;
	
			for(j=i+i; j<=n; j+=i)
			{
				if(x[j]==0)
					x[j]=j-(j/i);
				else
					x[j]=x[j]-x[j]/i;
			}
		}
		else		
			s += x[i];
    }
    printf("%d",2*s+1);
}