Cod sursa(job #665307)
Utilizator | Data | 21 ianuarie 2012 22:06:10 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.27 kb |
#include<fstream>
using namespace std;
char v[2000001];
int n,cnt,i,j;
int main()
{
ifstream fin("ciur.in");
ofstream fout("ciur.out");
fin>>n;
cnt=1;
for(i=3;i<=n;i+=2)
if(!v[i])
{
for(j=2;j*i<=n;++j)
v[i*j]=1;
++cnt;
}
fout<<cnt;
}