Cod sursa(job #1237702)
Utilizator | Data | 4 octombrie 2014 17:50:42 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.35 kb |
#include <fstream>
using namespace std;
ifstream f("ciur.in");
ofstream g("ciur.out");
int n,i,j,nr;
bool prim[2000005];
int main()
{
f>>n;
nr=0;
for(i=2;i<=n;i++)
if(!prim[i])
{
nr++;
for(j=2*i;j<=n;j+=i)
prim[j]=true;
}
g<<nr;
return 0;
}