Cod sursa(job #1124540)
Utilizator | Data | 26 februarie 2014 12:39:16 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.3 kb |
#include<fstream>
using namespace std;
ifstream cin ("ciur.in");
ofstream cout("ciur.out");
int n,i,j,k;
char prim [2000003];
int main ()
{
cin>>n;
for (i=1;i<=n;i++)
prim[i]=1;
for (i=2;i<=n;i++)
if (prim[i]==1){
k++;
for (j=i+i;j<=n;j+=i)
prim[j]=0;}
cout<<k;
return 0;
}