Cod sursa(job #635208)
Utilizator | Data | 18 noiembrie 2011 19:24:08 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 30 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.33 kb |
#include<fstream>
#include<iostream>
#include <string>
using namespace std;
bool lol[2000001];
int main(){
ifstream f("ciur.in");
ofstream g("ciur.out");
int n;
f>>n;
int i,ct=0,j;
for(i=2;i<=n;++i)
{
if(lol[i]!=true){
++ct;
for(j=i;j*i<=n;++j)
{
lol[i*j]=true;
}
}
}
g<<ct;
return 0;
}