Cod sursa(job #2222738)

Utilizator Andrei-27Arhire Andrei Andrei-27 Data 17 iulie 2018 22:30:05
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.31 kb
Raporteaza aceasta sursa 
#include <iostream>
#include <fstream>
using namespace std;
int main(){
ifstream f("ciur.in");
ofstream g("ciur.out");
int i,j,n,cnt=0;
char prim[2000005];
f>>n;
for(i=1;i<=n;i++) prim[i]=1;
for(i=2;i<=n;i++)
    if(prim[i])
    {cnt++;
    for(j=i+i;j<=n;j+=i) prim[j]=0;}
g<<cnt;
return 0;}