5.Algorithm Gossip: 老鼠走迷官（一）

5.Algorithm Gossip:老鼠走迷官（一）

说明老鼠走迷宫是递回求解的基本题型，我们在二维阵列中使用2表示迷宫墙壁，使用1来表示老鼠的行走路径，试以程式求出由入口至出口的路径。

解法老鼠的走法有上、左、下、右四个方向，在每前进一格之后就选一个方向前进，无法前进时退回选择下一个可前进方向，如此在阵列中依序测试四个方向，直到走到出口为止，这是递回的基本题，请直接看程式应就可以理解。

// MouseLost.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include <stdio.h>
#include <stdlib.h>

int visit(int, int);

int maze[7][7] = {{2, 2, 2, 2, 2, 2, 2},
{2, 0, 0, 0, 0, 0, 2},
{2, 0, 2, 0, 2, 0, 2},
{2, 0, 0, 2, 0, 2, 2},
{2, 2, 0, 2, 0, 2, 2},
{2, 0, 0, 0, 0, 0, 2},
{2, 2, 2, 2, 2, 2, 2}};

int startI = 1, startJ = 1;  // 入口
int endI = 5, endJ = 5;  // 出口
int success = 0;

int main(int argc, char* argv[])
{

int i, j;

printf("显示迷宫：\n");
for(i = 0; i < 7; i++) {
for(j = 0; j < 7; j++)
if(maze[i][j] == 2)
printf("█");
else
printf("  ");
printf("\n");
}

if(visit(startI, startJ) == 0)
printf("\n没有找到出口！\n");
else {
printf("\n显示路径：\n");
for(i = 0; i < 7; i++) {
for(j = 0; j < 7; j++) {
if(maze[i][j] == 2)
printf("█");
else if(maze[i][j] == 1)
printf("◇");
else
printf("  ");
}
printf("\n");
}
}

return 0;
}

int visit(int i, int j) {
maze[i][j] = 1;

if(i == endI && j == endJ)
success = 1;

if(success != 1 && maze[i][j+1] == 0) visit(i, j+1);
if(success != 1 && maze[i+1][j] == 0) visit(i+1, j);
if(success != 1 && maze[i][j-1] == 0) visit(i, j-1);
if(success != 1 && maze[i-1][j] == 0) visit(i-1, j);

if(success != 1)
maze[i][j] = 0;

return success;

}

public class MouseLost1 {

static int startI = 1, startJ = 1;
static int endI = 5, endJ = 5;
static int success = 0;

static int[][] maze = new int[][]{{2, 2, 2, 2, 2, 2, 2},
{2, 0, 0, 0, 0, 0, 2},
{2, 0, 2, 0, 2, 0, 2},
{2, 0, 0, 2, 0, 2, 2},
{2, 2, 0, 2, 0, 2, 2},
{2, 0, 0, 0, 0, 0, 2},
{2, 2, 2, 2, 2, 2, 2}};

public static int Visit(int i ,int j){
maze[i][j] = 1;

if(i == endI && j == endJ){
success = 1;
}
if(success != 1 && maze[i][j+1] == 0) Visit(i, j+1);
if(success != 1 && maze[i+1][j] == 0) Visit(i+1, j);
if(success != 1 && maze[i][j-1] == 0) Visit(i, j-1);
if(success != 1 && maze[i-1][j] == 0) Visit(i-1, j);

if(success != 1){
maze[i][j] = 0;
}
return success;
}

public static void main(String[] args){
int i, j;
System.out.println("显示迷宫");
for(i=0; i < 7; i++){
for (j = 0;  j < 7; j++) {
if(maze[i][j] == 2){
System.out.print("█");
}
else{
System.out.print(" ");
}
}
System.out.println();
}
if(Visit(startI, startJ) == 0){
System.out.println("没有找到出口");
}
else{
System.out.println("显示路径");

for(i = 0; i < 7; i++) {
for(j = 0; j < 7; j++) {
if(maze[i][j] == 2)
System.out.print("█");
else if(maze[i][j] == 1)
System.out.print("-");
else
System.out.print(" ");
}
System.out.println();
}
}
}
}

显示迷宫
███████
█          █
█ █   █  █
█    █  ██
██  █  ██
█          █
███████
显示路径
███████
█-         █
█- █  █  █
█--  █  ██
██- █  ██
█ ----     █
███████