Cod sursa(job #168082)
Utilizator | Data | 30 martie 2008 18:22:53 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 0 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.35 kb |
#include<fstream.h>
int ciur[130000];
long n,k;
ifstream f("prim.in");
ofstream g("prim.out");
int main()
{
f>>n;
for (int i=2;i<=n;++i)
ciur[i]=1;
for (i=2;i*i<=n;++i)
if (ciur[i])
for (intj=i*i;j<=n;j+=i)
ciur[j] = 0;
for(i=2;i<=n;i++)
if(ciur[i])
k++;
g<<k;
f.close();
g.close();
return 0;
}