Cod sursa(job #2782646)
Utilizator | Data | 12 octombrie 2021 19:52:45 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva educationala | Marime | 0.41 kb |
#include<iostream>
#include<fstream>
#include<bitset>
using namespace std;
ifstream f("ciur.in");
ofstream g("ciur.out");
int cnt,n;
bitset<2000001> v;
int main()
{
f>>n;
for(int i=2;i<=n;i++)
{
if(v[i]==false)
for(int j=i*2;j<=n;j=j+i)
v[j]=true;
}
for(int i=2;i<=n;i++)
{
if(v[i]==false)
cnt++;
}
g<<cnt;
}