Cod sursa(job #662971)
Utilizator | Data | 17 ianuarie 2012 16:35:35 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.32 kb |
#include<stdio.h>
using namespace std;
bool je[2000020];
long long i,j,n,nr;
int main()
{
freopen("ciur.in","r",stdin);
freopen("ciur.out","w",stdout);
scanf("%d",&n);
for(i=2;i<=n;i++)
if(je[i]==0)
{
if(i*i<=n)
{
for(j=1LL*i*i;j<=n;j=j+i)
je[j]=1;
}
nr++;
}
printf("%d\n",nr);
return 0;
}