在遞迴中不斷重複以下步驟： 若要將N層從X轉移到Z，則需要將N-1層從X轉移到Y，再將第N層從X轉移到Z，最後將N-1層從Y轉移到Z；將N層從從X轉移到Y、Y轉移到Z、Y轉移到X、Z轉移到X、Z轉移到Y也類似。 返回條件：N == 1時，第N層直接轉移到Z。(從X轉移到Z情況)

import java.util.Scanner;

public class HanoiTower 
{
    private int steps = 0; //完成遊戲需要的最少步數
    public HanoiTower(){}

    public int getSteps(){
        return
 
 steps;
    }
    /*
    public int getSteps(int num){
        int steps;
        if(num == 1){
           steps = 1;
           return steps;
        }
        steps = 2*this.getSteps(num-1)+1;
        return steps;
    }
    */
    public void printXToZ(int num){
        if(num == 1){
            System.out
 
.print(num + "->Z  ");
            steps++;
            return;
        }
        printXToY(num - 1);
        System.out.print(num + "->Z  ");
        steps++;
        printYToZ(num - 1);
    }

    public void printYToZ(int num){
        if(num == 1){
            System.out.print(num + "->Z  "
 
);
            steps++;
            return;
        }
        printYToX(num - 1);
        System.out.print(num + "->Z  ");
        steps++;
        printXToZ(num - 1);
    }

    public void printYToX(int num){
        if(num == 1){
            System.out.print(num + "->x  ");
            steps++;
            return;
        }
        printYToZ(num - 1);
        System.out.print(num + "->x  ");
        steps++;
        printZToX(num - 1);
    }

    public void printZToX(int num){
        if(num == 1){
            System.out.print(num + "->x  ");
            steps++;
            return;
        }
        printZToY(num - 1);
        System.out.print(num + "->x  ");
        steps++;
        printYToX(num - 1);
    }

    public void printXToY(int num){
        if(num == 1){
            System.out.print(num + "->y  ");
            steps++;
            return;
        }
        printXToZ(num - 1);
        System.out.print(num + "->y  ");
        steps++;
        printZToY(num - 1);
    }

    public void printZToY(int num){
        if(num == 1){
            System.out.print(num + "->y  ");
            steps++;
            return;
        }
        printZToX(num - 1);
        System.out.print(num + "->y  ");
        steps++;
        printXToY(num - 1);
    }

    public static void main(String[] args) 
    {
        int num;//漢諾塔層數
        Scanner scanner = new Scanner(System.in);
        System.out.println("Please input the floors of HanoiTower:");
        num = scanner.nextInt();
        HanoiTower hanoiTower = new HanoiTower();

        hanoiTower.printXToZ(num);//將漢諾塔從X位置移到Z位置
        System.out.println();
        System.out.println("Steps:" + hanoiTower.getSteps());
    }
}