链栈

链栈的表示

• 运算是受限的单链表，只能在链表头部进行操作，故没有必要附加头结点。栈顶指针就是链表的头指针。

C++代码实现

#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