Cod sursa(job #402360)
Utilizator | Data | 23 februarie 2010 20:18:02 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 30 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.29 kb |
#include<stdio.h>
int i,j,nr,n,v[2000000];
int main()
{freopen("ciur.in","r",stdin);
freopen("ciur.out","w",stdout);
scanf("%d",&n);
if(n>=2)
{v[2]=1;nr=1;
for(i=3;i<=n;i+=2)
v[i]=1;
for(i=3;i<=n;i+=2)
if(v[i])
{nr++;
for(j=i+i;j<=n;j=j+i)
v[j]=0;
}
}
printf("%d",nr);
}