11729번 하노이 탑 이동 순서

단계별로 풀어보기 - 재귀 - 4단계

https://www.acmicpc.net/problem/11729

#include <iostream>
#include <cmath>
using namespace std;
void hanoi(int N,int first,int middle,int last)
{
    if(N==1)
    {
        cout<<first<<" "<<middle<<"\n";
    }
    else
    {
        hanoi(N-1,first,last,middle);
        cout<<first<<" "<<middle<<"\n";
        hanoi(N-1,last,middle,first);
    }
}

int main()
{
    int num;
    cin>>num;
    cout<<(int)pow(2,num)-1<<"\n";
    hanoi(num,1,3,2);
}