Cod sursa(job #2081294)
Utilizator | Data | 4 decembrie 2017 16:07:57 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 40 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.34 kb |
#include <fstream>
using namespace std;
ifstream fin("ciur.in");
ofstream fout("ciur.out");
char v[1000010];
int n,i,ct,j,a;
int main()
{
fin>>n;
for(i=2;i*i<n;i++)
if(v[i]==0)
for(j=i*i;j<=n;j=j+i)
v[j]=1;
for(i=2;i<=n;i++)
if(v[i]==0)
ct++;
fout<<ct;
return 0;
}