//By LYLtim

#include<stdio.h>

const int di[4] = {0,1,0,-1},
          dj[4] = {1,0,-1,0};

unsigned 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 { int i, j; } que[23] = {0};

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

int main(void)
{
	while (head != tail) {
		head = (head + 1) % 23;
		int i;
		for (i = 0; i < 4; i++)
			if (que[head].i + di[i] >= 0 && que[head].i + di[i] < 5
				&& que[head].j + dj[i] >= 0 && que[head].j +dj[i] < 5
				&& maze[que[head].i + di[i]][que[head].j +dj[i]] == 0) {
					que[tail = (tail + 1) % 23].i = que[head].i + di[i];
					que[tail].j = que[head].j +dj[i];
					maze[que[head].i + di[i]][que[head].j +dj[i]] = 2;
					if (que[head].i + di[i] == 4 && que[head].j +dj[i] == 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.