尋找迷宮中的最少步數的一個深度優先遍歷的小算法

package algorithm;

public class Algorithm2 {

/**
 *
 *  s 0 1 0
 *  0 0 0 0
 *  0 0 1 0
 *  0 1 e 0
 *  0 0 0 1
 *
 *
 *  豎軸爲x軸
 *  橫軸爲Y軸
 */
 

	/**
	 * 迷宮找最短路徑 0代表平地,1代表障礙物,s代表起點，e代表終點 (起點和終點肯定也是0)
	 */


	static int[][] next = {
			{0, 1},//右
			{1, 0},//下
			{0, -1},//左
			{-1, 0}//上
	};
	static int[][] allLocation = new int[50][50];
	static int[][] marks = new int[50][50];

	static {
		//我這列從1,1開始賦值
		allLocation[1][1] = 0;
		allLocation[1][2] = 0;
		allLocation[1][3] = 1;
		allLocation[1][4] = 0;

		allLocation[2][1] = 0;
		allLocation[2][2] = 0;
		allLocation[2][3] = 0;
		allLocation[2][4] = 0;

		allLocation[3][1] = 0;
		allLocation[3][2] = 0;
		allLocation[3][3] = 1;
		allLocation[3][4] = 0;

		allLocation[4][1] = 0;
		allLocation[4][2] = 1;
		allLocation[4][3] = 0;
		allLocation[4][4] = 0;

		allLocation[5][1] = 0;
		allLocation[5][2] = 0;
		allLocation[5][3] = 0;
		allLocation[5][4] = 1;

	}

	static int endX, endY;//終點
	static int startX, startY;//起點
	static int min = 99999;
	static int n = 5;//行數
	static int m = 4;//列數


	public static void main(String[] args) {
		startX = 1;
		startY = 1;

		endX = 4;
		endY = 3;

		marks[startX][startY] = 1;

		dfs(startX,startY,0);

		System.out.println("最短步數爲:"+min);

	}

	//深度優先遍歷
	public static void dfs(int x, int y, int step) {

		int tx, ty, k;

		//判斷是否到達終點的位置
		if (x == endX && y == endY) {
			//更新最小值
			if (step < min) {
				min = step;
			}


			return;
		}

		//枚舉四種走法 這裏的走法是 右 下 左 上
		for (k = 0; k <= 3; k++) {
			//計算下一個點的座標
			tx = x + next[k][0];
			ty = y + next[k][1];

			//判斷是否越界
			if (tx < 1 || tx > n || ty < 1 || ty > m) {
				continue;
			}

			//判斷該點是否爲障礙物或者已經在路徑中
			if (allLocation[tx][ty] == 0 && marks[tx][ty] == 0) {
				marks[tx][ty] = 1;//已經走過了
				dfs(tx, ty, step + 1);
				marks[tx][ty] = 0;//取消標記位
			}


		}

		return;
	}


}