栈

栈的顺序存储结构

#define maxsize 100
typedef struct{
	Elemtype  data[maxsize];
	int top;
}sqstack;
int InitStack(sqstack *s)
{
	//创建一个空栈由指针s指向
	if((s=(sqstack *)malloc(sizeof(sqstack)))==NULL)
	return ERROR;
	s->top=-1;
	return OK; 
 } 
 int StackEmpty(sqstack *s)
 {
 	return (s->t==-1?true:false);
 }
 int StackFull(sqstack *s)
 {
 	//判栈为满栈时返回值为真
	 return (s->top==maxsize-1?true:false); 
  } 
  //入栈 
  int Push(sqstack *s,Elemtype e)
  {
  	if(StackFull(s))return error;
  	s->top++;
  	s->data[s->top]=e;
  	return OK;
  }
  //出栈 
  int Pop(sqstack *s,Elemtype *e)
  {
  	if(StackEmpty(s))return ERROR;
  	*e=s->data[s->top];
  	s->top--;
  	return OK;
  }
  //取栈顶元素 
  int GetTop(sqstack *s,Elemtype *e)
  {
  	if(StackEmpty(s))return ERROR;
  	*e=s->data[s->top];
  	return OK;
  }

栈的链式存储结构

typedef struct node
{
	Elemtype data;
	struct node* next;
 } StackNode,*LinkStack;
 LinkStack top;//top为栈顶指针
 LinkStack InitStack()
 {
 	return NULL;
  } 
  int StackEmpty(LinkStack top)
  {
  	return(top==NULL?true:false);
  }
  //进栈 
  void Push(LinkStack top,Elemtype e)
  {
  StackNode *s;
  s=(StackNode *)malloc(sizeof(StackNode));
  s->data=e;
  s->next=top;
  top=s;	
  }
  
  //出栈
  int Pop(LinkStack top,Elemtype *e)
  {
  	StackNode *p;
  	if(StackEmpty(top))return error;
  	*e=top->data;
  	p=top;
  	top=top->next;
  	free(p);
  	return OK;
   }