Cod sursa(job #658850)
Utilizator | Data | 9 ianuarie 2012 18:21:12 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 30 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.31 kb |
#include<iostream>
#include<fstream>
using namespace std;
ifstream f("ciur.in");
ofstream g("ciur.out");
int prim(int a)
{
for (int i=2; i*i<=a;i++)
if (a%i==0)
return 0;
return 1;
}
int main()
{
int i,n,nr=0;
f>>n;
for (i=2;i<=n;i++)
if (prim(i))
nr++;
g<<nr;
return 0;
}