迷宫求解
#define OVERFLOW -2
#define ERROR 0
#define NULL 0
#define true 1
#define TRUE 1
#define false 0
#define FALSE 0
#define STACK_INIT_SIZE 100
#define STACKINCREMENT 10
#include <stdio.h>
#include <stdlib.h>
/*
初始化迷宫,1表示通道,0表示墙
*/
int maze[8][8] = {
1,1,0,1,1,1,0,1,
1,1,0,1,1,1,0,1,
1,1,1,1,0,0,1,1,
1,0,0,0,1,1,1,1,
1,1,1,0,1,1,1,1,
1,0,1,1,1,0,1,1,
1,0,0,0,1,0,0,1,
0,1,1,1,1,1,1,1
};
//定义栈元素类型
typedef struct MStackElem
{
int x;//x坐标
int y;//y坐标
int val;//maze[x][y]的值
}MStackElem;
//定义栈
typedef struct {
MStackElem * base;
MStackElem * top;
int stackSize;
}MStack;
//=============Stack的实现========================
//初始化栈-------构造一个空栈
void initStack(MStack *s) {
s->base = (MStackElem *)malloc(STACK_INIT_SIZE * sizeof(MStackElem));
if (!s->base) {
printf("in initStack()...Failed to initalize the MStack ,no enough space! exit now. ");
exit(OVERFLOW);//存储分配失败
}
s->top = s->base;
s->stackSize = STACK_INIT_SIZE;
}
//向栈中添加元素
void push(MStack *s,MStackElem e) {
//向栈中添加元素前先判断栈是否还有空间容纳新元素
if (s->top - s->base >= s->stackSize) { //栈满,追加元素
s->base = (MStackElem *)realloc(s->base, (STACK_INIT_SIZE+STACKINCREMENT) * sizeof(MStackElem));
if (!s->base) {
printf("in push()...Failed to realloc the MStack ,no enough space! exit now. ");
exit(OVERFLOW);//存储分配失败
}
s->top = s->base + s->stackSize; //因为是重新分配了空间,所以base的值其实已经改变,所以top的值也就相应的改变,才能指向新的迷宫栈
s->stackSize += STACKINCREMENT;
}
//将新元素加到栈顶
*(s->top++) = e;
}
//获得栈顶元素
MStackElem getTop(MStack *s) {
if (s->top == s->base) {
printf("in getTop(),empty stack! exit now. ");
exit(ERROR);
}
else {
return *(s->top - 1);
}
}
//删除栈顶元素
void pop(MStack *s) {
//若栈不为空,则删除s的栈顶元素
if (s->top == s->base) {
printf("in pop(),empty stack! exit now. ");
exit(ERROR);
}
else {
--(s->top);
}
}
//=====================================求解迷宫的相关操作=====================//
//构造两个栈,一个用来保存探索中的全部路径,一个用来保存有效路径
MStack realPath,path;
//判断当前位置是否走过
int unPass(MStack path,MStackElem cur) {//这里不能传path的地址,否则在遍历过程中它的top值就真的被改了 !!
int flag = 1;
while(path.top != path.base)
{
MStackElem e = *(path.top - 1);
if (e.x == cur.x&& e.y == cur.y)
{
flag = 0;
}
//每循环一次令头指针下移一个位置
(path.top)--;
}
return flag;
}
//获得东面相邻的位置
MStackElem getEast(MStackElem cur) {
if(cur.y != 7) {//当y==7时已到了迷宫右边界,不能再向东(右)行了
cur.y += 1;
cur.val = maze[cur.x][cur.y];
}
return cur;// 当y==7时返回的是它本身
}
//获得南面相邻的位置
MStackElem getSouth(MStackElem cur) {
if(cur.x != 7) {//当x==7时已到了迷宫下边界,不能再向南(下)行了
cur.x += 1;
cur.val = maze[cur.x][cur.y];
}
return cur;// 当x==7时返回的是它本身
}
//获得西面相邻的位置
MStackElem getWest(MStackElem cur) {
if(cur.y != 0) {//当y==0时已到了迷宫左边界,不能再向西(左)行了
cur.y -= 1;
cur.val = maze[cur.x][cur.y];
}
return cur;// 当y==0时返回的是它本身
}
//获得北面相邻的位置
MStackElem getNorth(MStackElem cur) {
if(cur.x != 0) {//当cur.x==0时表示在迷宫的上边界,不能再向北(上)行了
cur.x -= 1;
cur.val = maze[cur.x][cur.y];
}
return cur;// 当cur.x==0时返回的还是它本身
}
//获得下一个可通行的位置,按东南西北的方向试探
MStackElem getNext(MStackElem cur) {
MStackElem next;
next.x = next.y=next.val = -1;
if(getEast(cur).val != 0 && unPass(path,getEast(cur))) {
next = getEast(cur);
}
else if(getSouth(cur).val != 0 && unPass(path,getSouth(cur))) {
next = getSouth(cur);
}
else if(getWest(cur).val != 0 && unPass(path,getWest(cur))) {
next = getWest(cur);
}
else if(getNorth(cur).val != 0 && unPass(path,getNorth(cur))) {
next = getNorth(cur);
}
//如果当前位置的四面或为墙或已走过,则返回的next的val值为-1
return next;
}
int getMazePath(){//获得迷宫路径的函数
MStackElem start,end,cur;
start.x = 0;
start.y = 0;
start.val = maze[start.x][start.y];
end.x = 7;
end.y = 7;
end.val = maze[end.x][end.y];
cur = start; //设定当前为位置为"入口位置"
//没有重载=运算符,可以这样用吗,结果对吗?试试吧:
/*
printf("%d",cur.x);
printf("%d",cur.y);
printf("%d",cur.val);
*/
//恩,结果是正确的,即可以通过cur=start来把start的值赋给cur.
//对了,想起来了,记得以前在学C++的复制构造函数时书上好像说过, 用=(等号)复制类对象时系统会调用由系统提供的复制的构造函数什么的,
//唉,记不清了,还是基础不扎实啊,以后可不能轻视基础了@_@ ...
do
{
if (unPass(path,cur)) {//如果当前位置未曾走到过
push(&realPath,cur);
push(&path,cur);
cur = getNext(cur);
if (cur.x == end.x && cur.y == end.y) { //到达出口了,则跳出循环,并返回true
//把出口结点放入路径中
push(&realPath,cur);
push(&path,cur);
//直接跳出函数(而不只是跳出这个循环 )
return true;
}
else if(cur.val == -1) {//当前位置的四面或为墙或已走过
//删除真实路径的栈顶元素
pop(&realPath);
cur = getTop(&realPath);//令cur指向栈顶元素
}
}
else {//如果当前位置已经走过,说明原来测试的方向不对,现在尝试其它方向
cur = getNext(cur);
if (cur.val == -1) {//仍不通,删除真实路径的栈顶元素
pop(&realPath);
cur = getTop(&realPath);//令cur指向栈顶元素
}
}
} while (cur.x != end.x || cur.y != end.y);
}
//打印迷宫路径
void printMazePath(MStack *s) {//为了安全,这里不传MStack的地址,以防在遍历的过程中把它们的top或base的值也修改了
/*注:这种方法实际是倒序打印出路径,让人看着别扭,所以我用下面的方法"倒序遍历这个栈 '
while (s->top != s->base) {
MStackElem e = *(s->top-1);
printf("maze[%d][%d]----->",e.x,e.y);
(s->top)--;
}
*/
MStackElem e;
while (s->base < (s->top-1)) {
e = *(s->base);//先指向栈底元素,以后依次向上增1
printf("maze[%d][%d]----->",e.x,e.y);
(s->base)++;
}
//最后一个结点没有后继,所以不再输出"------>"
e = *(s->base);
printf("maze[%d][%d]",e.x,e.y);
}
main(){
//初始化栈
initStack(&realPath);
initStack(&path);
getMazePath();
printf("The path of through the maze is:\n\n");
printMazePath(&realPath);
getchar();
}
浙公网安备 33010602011771号