汉诺塔递归实现——Java代码

在递归中不断重复以下步骤: 若要将N层从X转移到Z,则需要将N-1层从X转移到Y,再将第N层从X转移到Z,最后将N-1层从Y转移到Z;将N层从从X转移到Y、Y转移到Z、Y转移到X、Z转移到X、Z转移到Y也类似。
返回条件:N == 1时,第N层直接转移到Z。(从X转移到Z情况)

以下N=5时运行的结果:
这里写图片描述

import java.util.Scanner;

public class HanoiTower 
{
    private int steps = 0;
    public HanoiTower(){}

    public int getSteps(){
        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;
        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);//将汉诺塔从X位置移到Z位置
        System.out.println();
        System.out.println("Steps:" + hanoiTower.getSteps());
    }
}

猜你喜欢

转载自blog.csdn.net/XindaBlack/article/details/82659917