Cod sursa(job #556338)
Utilizator | Data | 16 martie 2011 08:44:28 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 30 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.33 kb |
#include<fstream>
using namespace std;
int ciur[2000000],n,i,j,k,v=0,z;
int main()
{ifstream f("ciur.in");
ofstream g("ciur.out");
f>>n;
for(i=2;i<n;i++)
ciur[i]=1;
for(i=2;i*i<=n;i++)
if(ciur[i])
for(j=2;j*i<n;j++)
ciur[i*j]=0;
for(i=2;i<n;i++)
if(ciur[i])
v=v+1;
g<<v<<" ";
f.close();
g.close();
return 0;
}