Cod sursa(job #2508513)
Utilizator | Data | 12 decembrie 2019 13:17:21 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva educationala | Marime | 0.37 kb |
#include<bits/stdc++.h>
using namespace std;
ifstream fin("ciur.in");
ofstream fout("ciur.out");
bool v[2000001];
int n;
int main()
{
fin>>n;
int nr=1;
for(int i=3; i<=n; i+=2)
{
if(v[i]==false)
{
nr++;
for(int j=i*2; j<=n; j+=i)
v[j]=true;
}
}
fout<<nr;
return 0;
}