Cod sursa(job #570667)
| Utilizator |  Oprinoiu Gabriel gaby123 |
Data | 3 aprilie 2011 13:57:17 |
|---|---|---|---|
| Problema | Ciurul lui Eratosthenes | Scor | 30 |
| Compilator | cpp | Status | done |
| Runda | Arhiva educationala | Marime | 0.22 kb |
#include<fstream.h>
int N,i,j,nr,a[2000001];
int main()
{
ifstream f("ciur.in");
ofstream g("ciur.out");
f>>N;
for(i=2;i<=N;i++)
{if(!a[i])
{nr++;
for(j=i*i;j<=N;j+=i)
a[j]=1;
}
}
g<<nr;
return 0;
}