Cod sursa(job #675544)
Utilizator | Data | 7 februarie 2012 18:50:28 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 0 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.28 kb |
#include<fstream>
using namespace std;
ifstream f("ciur.in");
ofstream g("ciur.out");
int N,nr;
char v[2000001];
int main()
{
int i,j;
f>>N;
for(i=2;i<=N;i++)
v[i]=0;
for(i=2;i<=N/2;i++)
if(v[i]==0)
{
nr++;
for(j=i*i;j<=N;j*=i)
v[i]=1;
}
g<<nr;
}