编程题4-迷宫寻路 （牛客网2018拼多多）

从(0,0)点出发到(4,4)点，0代表路，1代表墙，求从原点到终点的步数。

输入为：
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
输出：
8

 

先用C语言写一个队列，在应用宽度优先搜索（BFS）

#include 
#include 
#include 

int Maze[5][5];
int map[5][5];

int dir[4][2] = { { 1,0 },{ -1,0 },{ 0,1 },{ 0,-1 } };
typedef struct Step {
	int x, y;
	int dis;
	struct Step * pre;
}Step;

struct QNode_ {

	Step *step;
	struct QNode_ *next;
};
typedef struct QNode_ QNode;

struct Queue_
{
	QNode * front; //队首
	QNode * rear; //队尾
};
typedef struct Queue_ Queue;
Queue MyQueue;

void Qcreat(Queue * queue)
{
	QNode * head;
	head = (QNode*)malloc(sizeof(QNode));
	queue->front = head;
	queue->rear = head;
	//	queue->front->data = 0;
	queue->front->next = NULL;
}

int QisEmpty(Queue * queue)
{
	if (queue->front == queue->rear)
	{
		return 1;
	}
	else
	{
		return 0;
	}
}

QNode * pop(Queue * queue)
{
	if (QisEmpty(queue) != 1)
	{
		QNode *node;
		node = queue->front->next;
		queue->front->next = node->next;
		if (node == queue->rear)
			queue->rear = queue->front;
		//		queue->front->data = 0;
		//		free(node);
		return node;
	}
	else
	{
		printf("队列为空\n");
	}

}

void push(Queue * queue, QNode * node)
{
	//QNode * node = (QNode*)malloc(sizeof(QNode));
	queue->rear->next = node;
	queue->rear = node;
	//	node->data = data;
	node->next = NULL;
}

void QDestory(Queue * queue)
{
	QNode * node;
	while (queue->front != NULL)
	{
		node = queue->front;
		queue->front = queue->front->next;
		free(node);
	}
}

int bfs(int x, int y)
{
	int i;
	QNode *s, *u, *v;
	s = (QNode*)malloc(sizeof(QNode));
	Step step_s;
	s->step = &step_s;
	s->step->pre = NULL;
	s->step->x = x;
	s->step->y = y;
	s->step->dis = 0;
	map[s->step->x][s->step->y] = 1;
	push(&MyQueue, s);
	while (!QisEmpty(&MyQueue))
	{
		u = pop(&MyQueue);
		for (i = 0; i < 4; i++)
		{
			Step *step_v;
			v = (QNode*)malloc(sizeof(QNode));
			step_v = (Step*)malloc(sizeof(Step));
			v->step = step_v;
			if (u->step->x == 4 && u->step->y == 4)
			{
				return u->step->dis;
			}
			v->step->x = u->step->x + dir[i][0];
			v->step->y = u->step->y + dir[i][1];
			v->step->pre = u->step;
			v->step->dis = u->step->dis + 1;
			if (Maze[v->step->x][v->step->y] == 0 && map[v->step->x][v->step->y] == 0 &&
				v->step->x >= 0 && v->step->x<5 && v->step->y >= 0 && v->step->y<5)
			{
				map[v->step->x][v->step->y] = 1;
				push(&MyQueue, v);
			}
		}
	}
	return 0;
}

int main(void)
{
	int i, j, distant;
	int M,N;

	Qcreat(&MyQueue);

	scanf("%d" ,&M);
	scanf("%d", &N);

	for (int i = 0; i < M; i++)
	{
		for (int j = 0; j < N; j++)
		{
			scanf("%d", &Maze[i][j]);
		}
	}

	distant = bfs(0, 0);

	printf("%d", distant);

	QDestory(&MyQueue);
	return 0;
}