蓝桥杯2017A java 第二题 跳蚱蜢

有9只盘子，排成1个圆圈。

其中8只盘子内装着8只蚱蜢，有一个是空盘。

我们把这些蚱蜢顺时针编号为 1~8

每只蚱蜢都可以跳到相邻的空盘中，

也可以再用点力，越过一个相邻的蚱蜢跳到空盘中。

请你计算一下，如果要使得蚱蜢们的队形改为按照逆时针排列，

并且保持空盘的位置不变（也就是1-8换位，2-7换位,...），至少要经过多少次跳跃？

注意：要求提交的是一个整数，请不要填写任何多余内容或说明文字。

图2. 跳蚱蜢

思路：广搜

package javaa;

import java.util.HashSet;
import java.util.LinkedList;
import java.util.Queue;

public class tiao3 {
	static long yuanshi = 912345678;
	static long mubiao = 987654321;
	static int length = 9;
	static int ans;
	static int l = 0;
	static int list[] = {1, 2, -1, -2};
	static HashSet<Long> hashSet = new HashSet<>();
	static Queue<jianmo> queue = new LinkedList<>();
	public static void main(String[] args) {
		jianmo firstJianmo = new jianmo(yuanshi, 8, 0);
		hashSet.add(yuanshi);
		queue.add(firstJianmo);
		
		while(!queue.isEmpty()) {
			System.out.println(l++);
			jianmo tanchudeJianmo = queue.poll();
			if (tanchudeJianmo.num == mubiao) {
				ans = tanchudeJianmo.step;
				System.out.println(ans);
				return;
			}else {
				jiaru(tanchudeJianmo);
			}
		}
	}
	
	public static void jiaru(jianmo tanchude) {
		for (int i = 0; i < list.length; i++) {
			int jiaohuanzhishu = (tanchude.ninezhishu + list[i] + length) % 9;
			int jiaohuangyinzi;
			if (jiaohuanzhishu == 0) {
				jiaohuangyinzi = (int) (tanchude.num % 10);
			}else {
				jiaohuangyinzi = (int) (tanchude.num % (long)Math.pow(10, jiaohuanzhishu + 1) / Math.pow(10, jiaohuanzhishu));
			}
			long jiaohuanghoudeshu = tanchude.num + (jiaohuangyinzi - 9) * (long)Math.pow(10, tanchude.ninezhishu) + (9 - jiaohuangyinzi) * (long)Math.pow(10, jiaohuanzhishu);
			if (hashSet.add(jiaohuanghoudeshu)) {
				queue.add(new jianmo(jiaohuanghoudeshu, jiaohuanzhishu, tanchude.step + 1));
			}
		}
	}
}

class jianmo{
	
	long num;
	int ninezhishu;
	int step;
	
	public jianmo(long num, int ninezhishu,int step) {
		// TODO Auto-generated constructor stub
		this.num = num;
		this.ninezhishu = ninezhishu;
		this.step = step;
	}
}