Cod sursa(job #428418)
Utilizator | Data | 29 martie 2010 11:26:59 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 0 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.31 kb |
#include <iostream>
#include <fstream>
#include <cmath>
using namespace std;
int main()
{
fstream f("ciur.in",ios::in);
fstream g("ciur.out",ios::out);
int x,i,prim=0,j;
char v[2000001];
f>>x;
for(i=2;i<=x/2;i++)
if(!v[i])
{
prim++;
for(j=i;j<=x;j+=i)
v[j]=1;
}
g<<prim;
}