Cod sursa(job #288836)
Utilizator | Data | 26 martie 2009 09:58:00 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.25 kb |
#include<fstream.h>
ifstream f("ciur.in");
ofstream g("ciur.out");
long i,nr,n,j;
char a[2000000];
int main()
{f>>n;
for(i=2;i<=n;i++)
{if(a[i]==0)
{nr++;
for(j=2*i;j<=n;j=j+i)
a[j]=1;}}
g<<nr;
f.close();
g.close();
return 0;}