Cod sursa(job #301565)
Utilizator | Data | 8 aprilie 2009 11:53:15 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 0 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.3 kb |
#include<fstream>
int n, k=0;
char prim[2000005];
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=k+1;
for(j=i+i;j<=n;j=j+i)
prim[j]=0;
}
g<<k;
return 0;
}