Cod sursa(job #732399)
Utilizator | Data | 10 aprilie 2012 14:08:01 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.34 kb |
#include<stdio.h>
int i,j,nr,x;
bool v[2000100];
int main ()
{
freopen("ciur.in","r",stdin);
freopen("ciur.out","w",stdout);
scanf("%d",&x);
v[1]=1;
for(i=2;i<=x;i++)
{
if(v[i]==0)
{
for(j=2;j<=x/i;j++)
{
v[j*i]=1;
}
}
}
for(i=1;i<=x;i++)
{
if(!v[i])
nr++;
}
printf("%d",nr);
return 0;
}