Cod sursa(job #1823963)

Utilizator bleo16783FMI Bleotiu Cristian bleo16783 Data 7 decembrie 2016 01:03:23
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.3 kb
Raporteaza aceasta sursa 
#include <iostream>
#include<fstream>
#include<bitset>
using namespace std;int k=1,n,i=1,j;bitset<1000000>a;int main(){ifstream f("ciur.in");f>>n;for(;((i*i)<<1)+(i<<1)<=n;++i)if(!a[i])for(j =((i*i)<<1)+(i<<1);(j<<1)<n;j+=(i<<1)+1)a[j]=1;for(i=1;(i<<1)<n;++i)if(!a[i])++k;ofstream g("ciur.out");g<<k;}