Cod sursa(job #301564)
Utilizator | Data | 8 aprilie 2009 11:52:57 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.28 kb |
#include<fstream>
int n,k=0;
char prim[2000005];
using namespace std;
int main(void)
{int i,j;
ifstream f("ciur.in");
ofstream g("ciur.out");
f>>n;
for(i=2;i<=n;i++)
prim[i]=1;
for(i=2;i<=n;i++)
if(prim[i])
{k++;
for(j=i+i;j<=n;j=j+i)
prim[j]=0;}
g<<k;
return 0;}