数据结构 C语言 双向链栈 迷宫问题

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

int count = 0;

typedef struct {
int x, y;
}position;

typedef struct node{
position data;
struct node *next, *pre;
}linkNode;

typedef struct {
linkNode *head;
linkNode *top;
}linkStack;

int initStack(linkStack *s)
{
s->head = (linkNode*)malloc(sizeof(linkNode));
s->top = s->head;
s->top->next = NULL;
s->top->pre = NULL;
}

int pushStack(linkStack *s, position value)
{
linkNode *p;
p = (linkNode*)malloc(sizeof(linkNode));
s->top->data = value;
p->next = s->top->next;
p->pre = s->top;
s->top->next = p;
s->top = p;
count++;
return 0;
}

int popStack(linkStack *s, position *nowPos)
{
s->top = s->top->pre;
free(s->top->next);
count--;
*nowPos = s->top->pre->data;
}

int main()
{
linkStack s;
linkNode *p;
position nowPos, startPos, endPos;
int i, m, n, j;
int **map;

initStack(&s);
printf("请输入行列数\n");
scanf("%d%d", &m, &n);
map = (int**)malloc(sizeof(int)*m);
for (i = 0; i < m; i++) {
map[i] = (int*)malloc(sizeof(int)*n);
}
printf("请输入地图:\n");
for (i = 0; i < m; i++) {
for (j = 0; j < n; j++) {
scanf("%d", &map[i][j]);
}
}
printf("\n");
printf("请输入开始位置和结束位置:\n");
scanf("%d %d", &startPos.x, &startPos.y);
scanf("%d %d", &endPos.x, &endPos.y);
nowPos = startPos;
pushStack(&s, nowPos);
while ((nowPos.x != endPos.x) || (nowPos.y != endPos.y)) {
if (0 == map[nowPos.x + 1][nowPos.y]) {
nowPos.x += 1;
map[nowPos.x][nowPos.y] = 2;
pushStack(&s, nowPos);
}
else if (0 == map[nowPos.x][nowPos.y - 1]) {
nowPos.y -= 1;
map[nowPos.x][nowPos.y] = 2;
pushStack(&s, nowPos);
}
else if (0 == map[nowPos.x - 1][nowPos.y]) {
nowPos.x -= 1;
map[nowPos.x][nowPos.y] = 2;
pushStack(&s, nowPos);
}
else if (0 == map[nowPos.x][nowPos.y + 1]) {
nowPos.y += 1;
map[nowPos.x][nowPos.y] = 2;
pushStack(&s, nowPos);
}
else {
map[nowPos.x][nowPos.y] = 2;
popStack(&s, &nowPos);
}
}
printf("路径为:\n");
for (i = 0, p = s.head; i < count; i++,p = p->next) {
printf("%d,%d\n", p->data.x, p->data.y);
}
system("pause");
return 0;
}