题解 | #汉诺塔问题#

import java.util.*;


public class Solution {
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 
     * @param n int整型 
     * @return string字符串ArrayList
     */
    public ArrayList<String> getSolution (int n) {
        // write code here
        // 定一个结果集
        ArrayList<String> result = new ArrayList<>();
        move(n, "left", "mid", "right", result);
        return result;
    }

    public void move(int n, String left, String mid, String right, ArrayList<String> result) {
        if(n == 1) {
            String res = "move from "+ left + " to " + right;
            result.add(res);
            return;
        }
        // 从左边移动到中间
        move(n -1, left, right, mid, result);
        String res = "move from "+ left + " to " + right;
        result.add(res);
        // 从中间移动到右边
        move(n - 1, mid, left, right, result);
    }
}