河内塔递归java

本文介绍了河内塔递归java的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

这是我使用递归解决河内塔的Java代码：

Here's my Java code for solving Tower of Hanoi using recursion:

/**here is a stack of N disks on the first of three poles (call them A, B and C) and your job is to move the disks from pole A to pole B without ever putting a larger disk on top of a smaller disk.*/ public class Hanoi { public static void main(String[] args) { playHanoi (2,"A","B","C"); } //move n disks from position "from" to "to" via "other" private static void playHanoi(int n, String from , String other, String to) { if (n == 0) return; if (n > 0) playHanoi(n-1, from, to, other); System.out.printf("Move one disk from pole %s to pole %s \n ", from, to); playHanoi(n-1, other, from, to); } }

我放置打印的地方吗方法有关系？另外，我可以这样做：

Does the place I put the print method matter? Also, can I do it like this:

playHanoi(n-1, from, to, other); playHanoi(n-1, other, from, to); System.out.printf("Move one disk from pole %s to pole %s \n ", from, to);

推荐答案

解决 Hanoy之塔这样的问题，只不过是定义了你想要完成工作的策略。和你的代码：

Solving Tower of Hanoy problem in this way, is nothing but defining the strategy of how you want to get the job done. And your code :

playHanoi(n-1, from, to, other); System.out.printf("Move one disk from pole %s to pole %s \n ", from, to); playHanoi(n-1, other, from, to);

基本上将您的策略​​定义为吼叫，

Basically defines your strategy to like bellow,

从 移动 n-1 磁盘 （源塔） 其他 （中间塔）。

然后移动 n 从 从 （源塔）到 到 （目标塔）的磁盘。

最后从 其他 （中间塔）移动 n-1 磁盘） to （目的地塔）。

Move n-1 disks from "from" (source tower) to "other" (intermediary tower).

Then move n th disk from "from" (source tower) to "to" (destination tower).

Finally move n-1 disks from "other" (intermediary tower) to "to" (destination tower).

您的 prinf 基本上是 2 nd步骤。

Your prinf basically does the 2 nd step.

现在，如果你写这样的代码：

Now if you write code like this:

playHanoi(n-1, from, to, other); playHanoi(n-1, other, from, to); System.out.printf("Move one disk from pole %s to pole %s \n ", from, to);

然后你基本上在做：

将 n-1 磁盘从 从 （源塔）移至 其他 （中间塔）。

然后移动 n-1 从 其他 （中间塔）到 到 （目标塔）的磁盘。

最后从 从 移动 n 磁盘（来源）塔）到 到 （目的地塔）。

Move n-1 disks from "from" (source tower) to "other" (intermediary tower).

Then move n-1 disks from "other" (intermediary tower) to "to" (destination tower).

Finally move n th disk from "from" (source tower) to "to" (destination tower).

在此策略中，执行 2 步骤后（从 移动所有 n-1 磁盘）其他 到 到 ）， 3 rd步骤无效（移动 n 磁盘从 从 到 到 ）！因为在 Tower of Hanoy 中你不能把较大的磁盘放在较小的磁盘上！

In this strategy, after doing the 2 nd step (moving all n-1 disks from "other" to "to"), 3 rd step becomes invalid(moving n th disk from "from" to "to")! Because in Tower of Hanoy you cant put a larger disk on a smaller one!

因此，选择第二个选项（策略）会导致您采用无效策略，这就是为什么您不能这样做的原因！

So choosing the second option(strategy) leads you to an invalid strategy, thats why you can not do that!