Cod sursa(job #583331)
Utilizator | Data | 19 aprilie 2011 18:26:32 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 30 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.32 kb |
#include <fstream>
using namespace std;
bool p[200003];
int main()
{
int n,i,j,nrp=0;
ifstream O_o("ciur.in");
O_o>>n;
O_o.close();
for(i=2;i<=n;++i)
if(!p[i])
{
++nrp;
for(j=i+i;j<=n;j+=i)
p[j]=1;
}
ofstream("ciur.out")<<nrp<<'\n';
return 0;
}