#define ERROR -2 #define OK 1 #define NULL 0 #define STACK_INT_SIZE 100 #define STACKINCREMENT 10 #include <stdio.h> typedef struct{ char *base; char *top; int stacksize; }SqStack;

int CreatStack(SqStack *S) {   (*S).base=(char *)malloc(STACK_INT_SIZE*sizeof(char));   if(!(*S).base) return ERROR;   (*S).top=(*S).base;   (*S).stacksize=STACK_INT_SIZE;   return OK; }

int StackLength(SqStack S) {SqStack p;   int length=0;   p=S;   while(p.base!=p.top)     {p.top--;       length++;     }   return length; }

int GetTop(SqStack S,char *e) {if(S.base==S.top)  return ERROR;   *e=*(S.top-1);   return OK; }

int Push(SqStack *S,char e) {   if((*S).top-(*S).base>=(*S).stacksize){   (*S).base=(char *)realloc((*S).base,((*S).stacksize+STACKINCREMENT)*sizeof(char));   if((*S).base)  exit(OVERFLOW);   (*S).top=(*S).base+(*S).stacksize;   (*S).stacksize+=STACKINCREMENT;   }   *((*S).top)++=e;   return OK; }

int Pop(SqStack *S,char *e) {if((*S).top==(*S).base)     return ERROR;   *e=*--(*S).top;   return OK; }

int DestroyStack(SqStack *S) {char *p;   while((*S).top!=(*S).base)   {p=(*S).top;   --(*S).top;   free(p);   }   return OK; }

int ClearStack(SqStack *S) {int length,n;   if(S->base==S->top) return OK;   else     {while(S->base!=S->top)           *(--S->top)=NULL;     }   return OK; }

int Print(SqStack *S) {   char *p;   for(p=S->top-1;p>=S->base;p--)     printf("%c",*p);   printf("\n");   return OK; }

int StackEmpty(SqStack S) {if(S.top==S.base)   return OK;   else   return  NULL; }

main() {SqStack *stack,*stack1,*stack2;   char *c,e;   stack=(SqStack *)malloc(sizeof(SqStack));   stack1=(SqStack *)malloc(sizeof(SqStack));   stack2=(SqStack *)malloc(sizeof(SqStack));   c=(char *)malloc(sizeof(char));   clrscr();   CreatStack(stack);   CreatStack(stack1);   CreatStack(stack2);   printf("Have created a stack,the length of it is %d\n",StackLength(*stack));   if(!StackEmpty(*stack))   printf("Stack is not empty!\n");   else   printf("Stack is empty!\n");   printf("Please input chars(End with '!'):\n");

  while((e=getchar())!='!')     Push(stack,e);   printf("Print the stack:");   Print(stack);   printf("The length of stack is%d\n",StackLength(*stack));   while(!StackEmpty(*stack)) {Pop(stack,c); Push(stack1,*c);}   while(!StackEmpty(*stack1)) {Pop(stack1,c); Push(stack2,*c);}   while(!StackEmpty(*stack2)) {Pop(stack2,c); Push(stack,*c);}   printf("Reverse print the stackis:");   Print(stack);   DestroyStack(stack);   DestroyStack(stack1);   DestroyStack(stack2);   getch(); }