Cod sursa(job #1774107)
Utilizator | Data | 8 octombrie 2016 16:17:33 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 20 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.34 kb |
#include <iostream>
#include <fstream>
using namespace std;
ifstream fin("ciur.in");
ofstream fout("ciur.out");
int n;
int prim(int x)
{
for(int i=2;i<=x/2;i++)
if(x%i==0) return 1;
return 0;
}
int main()
{
fin>>n;int k=0;
for(int i=1;i<=n;i=i+2)
if(prim(i)==0) k++;
fout<<k;
return 0;
}