Cod sursa(job #296043)
Utilizator | Dragomir Lucian lucianvn | Data | 4 aprilie 2009 01:42:13 |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 20 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.36 kb |
#include<fstream.h>
ifstream intrare ("ciur.in");
ofstream iesire ("ciur.out");
long long unsigned v[100000];
int main()
{
long long unsigned n,j;
unsigned nr,i;
intrare>>n;
for(i=2;i<=7;i++)
{
if(v[i]==0)
{
for(j=i+i;j<=n;j+=i)
{
v[j]=1;
}
}
}
nr=0;
for(i=2;i<=n;i++)
{
if(v[i]==0) nr++;
}
iesire<<nr;
return 0;
}