Cod sursa(job #2508510)
Utilizator | Data | 12 decembrie 2019 13:14:05 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 50 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva educationala | Marime | 0.36 kb |
#include<bits/stdc++.h>
using namespace std;
ifstream fin("ciur.in");
ofstream fout("ciur.out");
int n,i,j,nr,v[2000001];
int main()
{
fin>>n;
nr=1;
for( i=3; i<=n; i+=2)
{
if(v[i]==0)
{
nr++;
for(j=i*2; j<=n; j+=i)
v[j]=1;
}
}
fout<<nr;
return 0;
}