Cod sursa(job #550129)
Utilizator | Data | 9 martie 2011 11:39:27 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 30 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.32 kb |
#include<fstream.h>
int v[20000000],i,j,n,p;
int main()
{
ifstream fin("ciur.in");
ofstream fout("ciur.out");
fin>>n;
for(i=1;i<=n;i++)
v[i]=i;
for(i=2;i<=n;i++)
{
if(v[i]>0)
{
p++;
for(j=i;j<=n;j=i+j)
{
v[j]=0;
}
}
}
fout<<p;
fin.close();
fout.close();
return 0;
}