C 数据结构：基于队列的广度优先搜索

C 数据结构：基于队列的广度优先搜索

一、实现

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

#define MAZE_ROW 6
#define MAZE_COL 8

typedef struct point
{
	int y_;
	int x_;
}Point;

typedef struct node
{
	Point data_;
	struct node* next_;
}Node;
typedef struct queue
{
	Node* front_;
	Node* rear_;
}Queue;


int maze[MAZE_ROW][MAZE_COL]={
1,1,1,1,1,1,1,1,
1,0,0,1,0,0,0,0,
1,1,0,1,0,1,1,1,
1,1,0,1,0,0,0,1,
0,0,0,0,0,1,1,1,
1,1,1,1,1,1,1,1};
Point path[MAZE_ROW][MAZE_COL];

void initQueue(Queue * queue);
int isEmpty(Queue *queue);
void enQueue(Queue *queue,Point ch);
Point deQueue(Queue *queue);
void destroyQueue(Queue *queue);

void disMaze();
void walkRoad(int y,int x,Point tp,Queue *queue);

int main()
{
	Point startPoint={4,0},endPoint={1,7};
	memset(path,0xff,sizeof(Point)*MAZE_ROW*MAZE_COL);
	Queue q;
	initQueue(&q);
	enQueue(&q,startPoint);
	int finishFlag=0;
	while(!isEmpty(&q))
	{
		disMaze();
		sleep(1);
		printf("\033c");
		Point tmpPoint=deQueue(&q);
		maze[tmpPoint.y_][tmpPoint.x_]=2;
		if(maze[tmpPoint.y_-1][tmpPoint.x_]>=0&&maze[tmpPoint.y_-1][tmpPoint.x_]==0)
			walkRoad(tmpPoint.y_-1,tmpPoint.x_,tmpPoint,&q);
		if(maze[tmpPoint.y_+1][tmpPoint.x_]<MAZE_ROW&&maze[tmpPoint.y_+1][tmpPoint.x_]==0)
			walkRoad(tmpPoint.y_+1,tmpPoint.x_,tmpPoint,&q);
		if(maze[tmpPoint.y_][tmpPoint.x_-1]>=0&&maze[tmpPoint.y_][tmpPoint.x_-1]==0)
			walkRoad(tmpPoint.y_,tmpPoint.x_-1,tmpPoint,&q);
		if(maze[tmpPoint.y_][tmpPoint.x_+1]<MAZE_COL&&maze[tmpPoint.y_][tmpPoint.x_+1]==0)
			walkRoad(tmpPoint.y_,tmpPoint.x_+1,tmpPoint,&q);
		if(endPoint.y_==tmpPoint.y_&&endPoint.x_==tmpPoint.x_)
		{
			finishFlag=1;
			break;
		}
	}
	if(1==finishFlag)
	{
	 	printf("find!\n");
		Point pp=endPoint;
		while(-1!=pp.y_)
		{
			printf("(%2d,%2d)",pp.y_,pp.x_);
			pp=path[pp.y_][pp.x_];
		}
		putchar(10);
	}
	if(0==finishFlag) printf("find none!\n");
	disMaze();
        destroyQueue(&q);	
	return 0;	
}

void initQueue(Queue * queue)
{
	queue->front_=queue->rear_=(Node*)malloc(sizeof(Node));
	if(NULL==queue->front_)	exit(-1);
	queue->front_->next_=NULL;	
}
int isEmpty(Queue *queue){ return queue->front_==queue->rear_; }
void enQueue(Queue *queue, Point ch)
{
	Node* ptr=(Node*)malloc(sizeof(Node));
	if(NULL==ptr) exit(-1);
	ptr->data_=ch;
	ptr->next_=NULL;
	queue->rear_->next_=ptr;
	queue->rear_=ptr;
}
Point deQueue(Queue *queue)
{
	Point tmp=queue->front_->next_->data_;
	if(queue->front_->next_==queue->rear_)
	{
		queue->front_=queue->rear_;
		free(queue->front_->next_);
		queue->front_->next_=NULL;
	}
	else
	{
		Node* tp=queue->front_->next_;
		queue->front_->next_=tp->next_;
		free(tp);
	}
	return tmp;
}
void destroyQueue(Queue *queue)
{
	Node *tp=queue->front_->next_;
	queue->front_->next_=NULL;
	queue->rear_=queue->front_;
	Node* t;
	while(tp)	
	{
		t=tp->next_;
		free(tp);
		tp=t;
	}
	free(queue->front_);
}

void disMaze()
{
	for(int j=0;j<MAZE_ROW;++j)
	{
		for(int i=0;i<MAZE_COL;++i)
		{
			if(1==maze[j][i]) printf("# ");
			else if(0==maze[j][i]) printf("  ");	
			else printf("o ");
		}
		puts("");
	}
}
void walkRoad(int y,int x,Point tp,Queue *queue)
{
	Point p={y,x};
	enQueue(queue,p);
	path[y][x]=tp;
}