数据结构——链栈

#include<iostream>
#include<stdlib.h>

using namespace std;

#define OVERFLOW -2
#define OK 1
#define ERROR -1

typedef int Status;
typedef int SElemType;

typedef struct StackNode {
	SElemType data;
	struct StackNode* next;
}StackNode, * LinkStack;

// 链栈初始化
void InitStack(LinkStack& S) {
	S = NULL;
}

// 判断链栈是否为空
Status StackEmpty(LinkStack S) {
	if (S == NULL) return 1;
	else return 0;
}

// 获取栈顶元素
Status GetTop(LinkStack S, SElemType& e) {
	if (StackEmpty(S)) return ERROR;
	e = S->data;
	return OK;
}

// 获取链栈长度
int GetLength(LinkStack S) {
	if (StackEmpty(S)) return 0;
	LinkStack p;
	p = S;
	int i = 0;
	while (p) {
		i++;
		p = p->next;
	}
	return i;
}

// 入栈
Status Push(LinkStack& S, SElemType e) {
	LinkStack p;
	p = new StackNode;
	if (!p) exit(OVERFLOW);
	p->data = e;
	p->next = S;
	S = p;
	return OK;
}

// 出栈
Status Pop(LinkStack& S, SElemType& e) {
	if (StackEmpty(S)) return ERROR;
	LinkStack p;
	e = S->data;
	p = S;
	S = S->next;
	delete p;
	p = NULL;
	return OK;
}

// 创建栈
void Create(LinkStack& S, int m) {
	SElemType x;
	int i;
	for (i = 1; i <= m; i++) {
		cout << "请输入第" << i << "个元素: ";
		cin >> x;
		Push(S, x);
	}
}

// 输出栈
void OutPut(LinkStack S) {
	LinkStack p;
	p = S;
	while (p) {
		cout << p->data << " ";
		p = p->next;
	}
	cout << endl;
}

int main()
{
	/*--------测试----------*/
	LinkStack S;
	SElemType e;
	int m;
	// 初始化链栈
	InitStack(S);

	cout << "请输入链栈的长度: ";
	cin >> m;
	Create(S, m);

	cout << "栈中元素为: ";
	OutPut(S);

	GetTop(S, e);
	cout << "栈顶元素为: " << e << endl;
	cout << "栈的长度为: " << GetLength(S) << endl;

	cout << "请输入入栈的元素: ";
	cin >> e;
	Push(S, e);
	cout << "栈中元素为: ";
	OutPut(S);

	Pop(S, e);
	cout << "弹出的元素为: " << e << endl;
	cout << "栈的长度为: " << GetLength(S) << endl;
	cout << "栈中元素为: ";
	OutPut(S);

	return 0;
}

请输入链栈的长度: 3

请输入第1个元素: 5

请输入第2个元素: 6

请输入第3个元素: 7

栈中元素为: 7 6 5

栈顶元素为: 7

栈的长度为: 3

请输入入栈的元素: 9

栈中元素为: 9 7 6 5

弹出的元素为: 9

栈的长度为: 3

栈中元素为: 7 6 5