Cod sursa(job #2266203)
Utilizator | Data | 22 octombrie 2018 14:45:34 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 0 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva educationala | Marime | 0.34 kb |
#include <fstream>
using namespace std;
ifstream f("ciur.in");
ofstream g("ciur.out");
int n,v[2000000],nrp;
int main()
{ f>>n;
for(int i=2;i<=n/2;++i)
if( v[i] == 0 )
for(int j=i+i;j<=n;j+=i) v[j]=1;
for(int i=2;i<=n/2;++i)
if( v[i] == 0 ) nrp++;
g<<nrp;
g.close();
return 0;
}