Cod sursa(job #655247)
Utilizator | szabo david emanuel david95 | Data | 1 ianuarie 2012 21:24:37 |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 20 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.42 kb |
#include<fstream>
using namespace std;
ifstream fin("ciur.in");
ofstream fout("ciur.out");
int prim( int n );
int main()
{
int k = 0;
long long n;
fin >> n;
for ( int j = 2; j <= n; j++ )
if ( prim(j) )
k++;
fout << k;
}
int prim( int n )
{
if( n == 2 )
return 1;
if ( n % 2 == 0 )
return 0;
for ( int d = 3; d <= n / 2; d++ )
if ( n % d == 0 )
return 0;
return 1;
}