Cod sursa(job #2925620)

Utilizator BlaugranasEnal Gemaledin Blaugranas Data 15 octombrie 2022 20:07:28
Problema Ciurul lui Eratosthenes Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.25 kb
Raporteaza aceasta sursa 
#include<bits/stdc++.h>
int n,i,j;
bitset<2000001> p;
int main()
{
    for(std::ifstream("ciur.in")>>n,i=3;i*i<=n;i+=2)
        if(!p[i])
            for(j=i*i;j<=n;p[j]=1,j+=2*i)
    return std::ofstream("ciur.out")<<(n+1)/2-p.count(),0;
}