Cod sursa(job #663992)
Utilizator | Data | 19 ianuarie 2012 13:21:38 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.32 kb |
#include<fstream>
using namespace std;
bool v[2000006];
int nr, n;
ifstream f("ciur.in");
ofstream g("ciur.out");
int ciur(int n)
{
int i,j;
for(i = 2 ; i <= n ; ++i)
if(v[i]==false)
{nr++;for(j=i+i;j<= n;j+=i)v[j]=true;}
return nr;
}
int main(){
f>>n;g<<ciur(n)<<'\n';
return 0;
}