Cod sursa(job #1079503)
Utilizator | Data | 12 ianuarie 2014 13:11:13 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 30 |
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,v[2000005],i,s,p,q;
int main()
{
f>>n;
v[1]=1;
s=1;
for(i=3;i<=n;i=i+2)
{
if(v[i]==0){
s++;
for(q=i+i;q<=n;q=q+i)
{
v[q]=1;
}}
}
g<<s;
return 0;
}