Cod sursa(job #429420)
Utilizator | Data | 30 martie 2010 09:36:06 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 30 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.38 kb |
#include<cstdio>
int a[2000001];
void ciur(int &n)
{
scanf("%d",&n);
int i,j;
for(i=2; i<=n; ++i)
a[i]=1;
int k=0;
for(i=2; i<=n; ++i)
{
if(a[i]==1)
{
k++;
for(j=2*i;j<=n; j+=i)
a[j]=0;
}
}
printf("%d",k);
}
int main()
{
freopen("ciur.in","r",stdin);
freopen("ciur.out","w",stdout);
int n;
ciur(n);
return 0;
}