Divisor.cpp

//Finding Divisor of a number (efficient)

#include "bits/stdc++.h"
using namespace std;

#define MAX 10000000
#define LL long long
bool Mark[MAX+10];
vector<LL>prime;

void sieve(){
    memset(Mark,0,sizeof(Mark));
    Mark[1]=Mark[0]=1;
    for(LL i=2; i<=MAX; i++){
        if(Mark[i]==0){
            prime.push_back(i);
            for(LL j=i*i; j<=MAX; j+=i){
                Mark[j]=1;
            }
        }
    }
}

vector<LL> Factor(LL num){
    int ind=0;
    vector<LL>res;
    res.push_back(1);
    while(prime[ind]*prime[ind]<=num){
        while(num%prime[ind]==0){
            res.push_back(prime[ind]);
            num/=prime[ind];
        }
        ind++;
    }
    if(num>1)res.push_back(num);
    return res;
}

int main(){
    sieve();
    LL num;
    cin>>num;
    vector<LL>PF=Factor(num);
    vector<LL>div;
    //for(int i=0; i<PF.size(); i++)cout<<PF[i]<<endl;
    cout<<endl;
    for(int i=0; i<PF.size(); i++){
        if(i==0)div.push_back(1);
        else{
            if(PF[i]!=PF[i-1]){
                int sz=div.size();
                for(int j=0; j<sz; j++){
                    div.push_back(PF[i]*div[j]);
                }
            }
            else{
                int ind=div.size()-1;
                div.push_back(PF[i]*div[ind]);
            }
        }
    }
    //cout<<div.size()<<endl;
    sort(div.begin(),div.end());
    for(int i=0; i<div.size(); i++){
        cout<<div[i]<<endl;
    }
    return 0;
}