Cod sursa(job #624570)
Utilizator | Data | 22 octombrie 2011 15:01:58 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 30 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.25 kb |
#include<fstream>
using namespace std;
int n,a[2000001],nr,i,j;
int main()
{
ifstream f("ciur.in");
ofstream g("ciur.out");
f>>n;
for(i=2;i<=n;i++)
{
if(a[i]==0)
nr++;
for(j=i+i;j<=n;j+=i)
a[j]=1;
}
g<<nr;
return 0;
}