用广度优先搜索解迷宫问题

定义一个二维数组：

int maze[5][5] = {
	0, 1, 0, 0, 0,
	0, 1, 0, 1, 0,
	0, 0, 0, 0, 0,
	0, 1, 1, 1, 0,
	0, 0, 0, 1, 0,
};

它表示一个迷宫，其中的1表示墙壁，0表示可以走的路，只能横着走或竖着走，不能斜着走，要求编程序找出从左上角到右下角的路线。程序如下：

//By LYLtim

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

const char
	Di[4] = {0,1,0,-1},
	Dj[4] = {1,0,-1,0};

char maze[5][5] = {
	2, 1, 0, 0, 0,
	0, 1, 0, 1, 0,
	0, 0, 0, 0, 0,
	0, 1, 1, 1, 0,
	0, 0, 0, 1, 0},
	head = 0, tail = 1;

struct {char i, j;} que[23];

void print_maze(void)
{
	char i, j;
	for (i = 0; i < 5; i++) {
		for (j = 0; j < 5; j++)
			printf("%hd ", maze[i][j]);
		putchar('\n');
	}
	printf("*********\n");
}

int main(void)
{
	while (head != tail) {
		head = (head + 1) % 23;
		char i;
		for (i = 0; i < 4; i++) {
			char Ni = que[head].i + Di[i], Nj = que[head].j + Dj[i];
			if (Ni >= 0 && Ni < 5 && Nj >= 0 && Nj < 5 && maze[Ni][Nj] == 0) {
					que[tail = (tail + 1) % 23].i = Ni;
					que[tail].j = Nj;
					maze[Ni][Nj] = 2;
					if (Ni == 4 && Nj == 4) {
						printf("Have path.\n"); exit(0);
					}
			}
		}
		print_maze();
	}
	printf("No path.\n");
	return 0;
}

运行结果如下：

2 1 0 0 0 
2 1 0 1 0 
0 0 0 0 0 
0 1 1 1 0 
0 0 0 1 0 
*********
2 1 0 0 0 
2 1 0 1 0 
2 0 0 0 0 
0 1 1 1 0 
0 0 0 1 0 
*********
2 1 0 0 0 
2 1 0 1 0 
2 2 0 0 0 
2 1 1 1 0 
0 0 0 1 0 
*********
2 1 0 0 0 
2 1 0 1 0 
2 2 2 0 0 
2 1 1 1 0 
0 0 0 1 0 
*********
2 1 0 0 0 
2 1 0 1 0 
2 2 2 0 0 
2 1 1 1 0 
2 0 0 1 0 
*********
2 1 0 0 0 
2 1 2 1 0 
2 2 2 2 0 
2 1 1 1 0 
2 0 0 1 0 
*********
2 1 0 0 0 
2 1 2 1 0 
2 2 2 2 0 
2 1 1 1 0 
2 2 0 1 0 
*********
2 1 0 0 0 
2 1 2 1 0 
2 2 2 2 2 
2 1 1 1 0 
2 2 0 1 0 
*********
2 1 2 0 0 
2 1 2 1 0 
2 2 2 2 2 
2 1 1 1 0 
2 2 0 1 0 
*********
2 1 2 0 0 
2 1 2 1 0 
2 2 2 2 2 
2 1 1 1 0 
2 2 2 1 0 
*********
2 1 2 0 0 
2 1 2 1 2 
2 2 2 2 2 
2 1 1 1 2 
2 2 2 1 0 
*********
2 1 2 2 0 
2 1 2 1 2 
2 2 2 2 2 
2 1 1 1 2 
2 2 2 1 0 
*********
2 1 2 2 0 
2 1 2 1 2 
2 2 2 2 2 
2 1 1 1 2 
2 2 2 1 0 
*********
Have path.