(C语言)栈的链式实现(数据结构九)

1.数据类型定义

在代码中为了清楚的表示一些错误和函数运行状态，我们预先定义一些变量来表示这些状态。在head.h头文件中有如下定义：

//定义数据结构中要用到的一些变量和类型
#ifndef HEAD_H
#define HEAD_H

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

#define TRUE  1
#define FALSE 0
#define OK    1
#define ERROR  0
#define INFEASIBLE -1
#define OVERFLOW   -2    //分配内存出错

typedef int  Status;     //函数返回值类型
typedef int  ElemType;   //用户定义的数据类型

#endif

2.数据结构实现

typedef struct Node{
	ElemType data;
	struct Node* next;
}Node,*pNode;

typedef struct Stack{
	pNode base;
	pNode top;
	int   length;
}Stack,*pStack;

3.栈的链式实现

LinkStack.h中代码如下：

#ifndef LINKSTACK_H
#define LINKSTACK_H

#include "head.h"

typedef struct Node{
	ElemType data;
	struct Node* next;
}Node,*pNode;

typedef struct Stack{
	pNode base;
	pNode top;
	int   length;
}Stack,*pStack;


//初始化栈
Status InitStack(pStack &S){
	S=(pStack)malloc(sizeof(Stack));
	if(!S) return OVERFLOW;
	S->length=0;
	S->base=(pNode)malloc(sizeof(Node));
	if(!S->base) return OVERFLOW;
	S->top=(pNode)malloc(sizeof(Node));
	if(!S->top) return OVERFLOW;
	S->top->next=S->base;
	return OK;
}

Status freeStack(pStack &S){
	free(S);
	S=NULL;
	return OK;
}

//清空栈
Status ClearStack(pStack &S){
	if(S==NULL) return ERROR;
	pNode p=S->top;
	while(p->next!=S->base){
		pNode q=p;
		p=p->next;
		free(q);
		q=NULL;
	}
	S->top=p;
	S->length=0;
	return OK;
}
//销毁栈
Status DestroyStack(pStack &S){
	if(S==NULL) return ERROR;
	ClearStack(S);
	free(S->base);
	S->base=NULL;
	free(S->top);
	S->top=NULL;
	freeStack(S);
	S==NULL;
	return OK;
}
//栈是否为空
Status StackEmpty(pStack S){
	return S->length<=0;
}
//栈长度
int StackLength(pStack S){
	return S->length;
}
//得到栈顶数据级e
Status GetTop(pStack S,ElemType &e){
	e=S->top->next->data;
	return OK;
}
//入栈
Status Push(pStack &S,ElemType e){
	if(S->length==0){
		S->base->data=e;
	}
	else{
		pNode p=S->top;
		p->data=e;
		pNode q=(pNode)malloc(sizeof(Node));
		q->next=p;
		S->top=q;
	}
	S->length++;
	return OK;
}
//出栈
Status Pop(pStack &S,ElemType &e){
	if (S->length<=0) return ERROR;
	if(S->length==1){
		e=S->base->data;
		S->length--;
	}else{
		pNode p=S->top;
		S->top=p->next;
		e=S->top->data;
		free(p);
		S->length--;
	}
	return OK;
}

Status print(ElemType e){
	printf("%d\n",e);
	return OK;
}

//用vistit遍历栈
Status StackTraverse(pStack S,Status(*visit)(ElemType)){
	pNode p=S->top;
	do 
	{
		p=p->next;
		(*visit)(p->data);
	} while (p!=S->base);
	return OK;
}
Status printStack(pStack S){
	if (S==NULL ||S->length==0) return ERROR;
	StackTraverse(S,print);
	return OK;
}


#endif

4.测试

#include "LinkStack.h"
void main(){
	pStack S;
	InitStack(S);
	for (int i=0;i<10;i++)
		Push(S,i);
	printf("栈长度：%d",StackLength(S));
	ElemType e;
	GetTop(S,e);
	printf("\n栈顶：%d",e);



	printf("\n遍历栈：\n");
	printStack(S);



	while(!StackEmpty(S)){
		ElemType e1;
		Pop(S,e1);
		printf("\n弹栈：%d",e1);
	}

	ClearStack(S);
	DestroyStack(S);

}

5.测试结果

栈长度：10
栈顶：9
遍历栈：
9
8
7
6
5
4
3
2
1
0

弹栈：9
弹栈：8
弹栈：7
弹栈：6
弹栈：5
弹栈：4
弹栈：3
弹栈：2
弹栈：1
弹栈：0