迷宫问题

迷宫问题/栈实现

#include"stdio.h"
#include"stdlib.h"
#define STACK_INIT_SIZE 50
#define STACK_INCREMENT 10
#define ERROR 0
#define OK 1
#define FALSE 0
#define TRUE 1
#define OVERFLOW -2
#define status int
#define ElemType Point
int a[7][9]={{1,1,0,1,1,1,1,1,1},
             {1,0,0,0,0,0,0,0,1},
             {1,0,1,1,1,1,1,1,1},
             {1,0,1,0,0,0,1,0,1},
             {1,0,1,0,1,0,1,0,1},
             {1,0,0,0,1,0,0,0,1},
             {1,1,1,1,1,1,1,0,1}};
bool trace[7][9]={0};
typedef struct {
     int x;
     int y;
     int d;
}Point;
typedef struct{
     int m;
     int n;
}position;
 position Move[4]={{1,0},{0,1},{-1,0},{0,-1}};
typedef struct{
      Point *base;
      Point *top;
      int stacksize;
}Stack;
status Initstack(Stack &s){
     s.base=(ElemType *)malloc(STACK_INIT_SIZE*sizeof(ElemType));
     if(!s.base) exit(OVERFLOW);
     s.top=s.base;
     s.stacksize=STACK_INIT_SIZE;
     return OK;
}
status Clearstack(Stack s){
     s.top=s.base;
}
status Emptystack(Stack s){
     if(s.top==s.base) return TRUE;
     return FALSE;
}
status Gettop(Stack s,ElemType &e){
     if(Emptystack(s)) return ERROR;
     e=*(s.top-1);
     return OK;
}
status Destroystack(Stack &s){
     free(s.base);
     return OK;

}
status Pushstack(Stack &s,ElemType &e){
     if(s.top-s.base>=s.stacksize){
     s.base=(ElemType *)realloc(s.base,(STACK_INIT_SIZE+STACK_INCREMENT)*sizeof(ElemType));
     if(!s.base) exit(OVERFLOW);
     s.top=s.base+s.stacksize;
     s.stacksize+=STACK_INCREMENT;
     }
     *s.top++=e;
     return OK;
}
status Popstack(Stack &s,ElemType &e){
     if(Emptystack(s)) return ERROR;
     e=*(--s.top);
     return OK;
}
int main(){
     Point start={6,7,0},end={0,2,0};
     int d=end.d,i=end.x,j=end.y;
     Point p,q;
     Stack s;
     Initstack(s);
     do{
          if(!a[i+Move[d].m][j+Move[d].n]&&!trace[i+Move[d].m][j+Move[d].n]){
               p.x=i;p.y=j;p.d=d;
               Pushstack(s,p);
               Gettop(s,p);
               printf("(%d,%d,%d)\n",p.x,p.y,p.d);
               trace[i][j]=1;
               i+=Move[d].m;j+=Move[d].n;
               if(i==start.x&&j==start.y) {
                    p.x=i;p.y=j;p.d=d;
                    Pushstack(s,p);break;
               }
               d=0;
          }
          else{
               d++;
          }
          while(d>=4){
               Gettop(s,p);
               printf("(%d,%d,%d)\n",p.x,p.y,p.d);
               Popstack(s,p);
               d=p.d;
               i=p.x;
               j=p.y;
               d++;
          }

     }while(!Emptystack(s));
     printf("maze as follows:\n\n");
     for(i=0;i<7;i++){
     for(j=0;j<9;j++)
          printf("%d ",a[i][j]);
          printf("\n");
     }
     printf("-----------------------------------\n");
     printf("start point: (%d,%d)\n",start.x,start.y);
     printf("end   point: (%d,%d)\n",end.x,end.y);
     printf("-----------------------------------\n");
     if(Emptystack(s)) printf("No way!\n");
     else while(!Emptystack(s)) {
           Gettop(s,p);
           printf("-> (%d,%d) ",p.x,p.y);
           Popstack(s,p);
     }
     printf("\n--------------------------------------------------------------------------------");
     Destroystack(s);
}