Cod sursa(job #412730)

Utilizator ionut.smartboyIonut Informaticianul ionut.smartboy Data 5 martie 2010 22:02:01
Problema Fractii Scor 30
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.32 kb
Raporteaza aceasta sursa 
#include<stdio.h>
FILE *in=fopen("fractii.in","r");
FILE *out=fopen("fractii.out","w");
long int n,nr,v[1000001],i,j;
int main()
{
	fscanf(in,"%ld",&n);
	for(i=2;i<=n;i++) v[i]=i-1;
	for(i=2;i<=n;i++)
	{
		nr=nr+v[i];
		for (j=i*2;j<=n;j=j+i) 
			v[j]=v[j]-v[i];
	}
	nr=(nr*2)+1;
	fprintf(out,"%ld",nr);
}