链栈的基本操作

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

#define OK 1
#define TRUE 1
#define ERROR 0
#define FALSE 0

typedef struct elem {
  int n;
}elem;

typedef struct StackNode {
  elem data;
  struct StackNode* next;
}StackNode,*LintStack;

LintStack S;

//初始化链表
int InitStack(LintStack &S) {
  S = NULL;
  return OK;
}

//判断是否为空
int EmptyStack(LintStack S) {
  if (S == NULL) return TRUE;
  else return FALSE;
}

//求长度
int LengthStack(LintStack S) {
  int i = 0;
  LintStack p = S;
  while (p) {
    p = p->next;
    i++;
  }
  return i;
}

//入栈
int Push(LintStack &S, elem e) {
  LintStack p = (LintStack)malloc(sizeof(StackNode));
  p->data = e;
  p->next = S;
  S = p;
  return OK;
}

//出栈
int Pop(LintStack &S, elem &e) {
  if (S == NULL) return ERROR;
  LintStack p = S;
  e = S->data;
  S = S->next;
  free(p);
  return OK;
}

//取栈顶元素
int GetTop(LintStack S, elem &e) {
  if (S == NULL) return ERROR;
  e = S->data;
  return OK;
}

//清空栈
int ClearStack(LintStack &S) {
  if (S == NULL) return OK;
  LintStack p=S->next;
  while (p != NULL) {
    free(S);
    S = p;
    p = S->next;
  }
  S = p;
  return OK;
}

//销毁栈
int DeleteStack(LintStack &S){
  LintStack p = S->next;
  while (p != NULL) {
    free(S);
    S = p;
    p = S->next;
  }
  free(S);
  free(p);
  return OK;
  
}

int main()
{
  return 0;
}