Cod sursa(job #1305819)
Utilizator | Data | 30 decembrie 2014 10:44:34 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.29 kb |
#include<fstream>
using namespace std;
ifstream f("ciur.in");
ofstream g("ciur.out");
int i,n,nr,j;
bool ciur[2000001];
int main()
{
f>>n;
for(i=2;i<=n;i++)
if(!ciur[i])
{
nr++;
for(j=i+i;j<=n;j+=i)
ciur[j]=1;
}
g<<nr<<'\n';
f.close();
g.close();
return 0;
}