分别用C和C++来实现一个链栈

下面通过分别用C和C++来实现一个链栈（链表实现），从中体会数据封装抽象的思想：

C语言实现：

 C++ Code 

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

struct Link
{
    int data;
    struct Link *next;
};

struct Stack
{
    struct Link *head;
    int size;
};

void StackInit(struct Stack *stack)
{
    stack->head = NULL;
    stack->size = 0;
}

void StackPush(struct Stack *stack, const int data)
{
    struct Link *node;
    node = (struct Link *)malloc(sizeof(struct Link));
    assert(node != NULL);
    node->data = data;
    node->next = stack->head;
    stack->head = node;
    ++stack->size;
}

int StackEmpty(struct Stack *stack)
{
    return (stack->size == 0);
}

int StackPop(struct Stack *stack, int *data)
{
    if (StackEmpty(stack))
    {
        return 0;
    }

    struct Link *tmp = stack->head;
    *data = stack->head->data;
    stack->head = stack->head->next;
    free(tmp);
    --stack->size;

    return 1;
}

void StackCleanup(struct Stack *stack)
{
    struct Link *tmp;
    while (stack->head)
    {
        tmp = stack->head;
        stack->head = stack->head->next;
        free(tmp);
    }

    stack->size = 0;
}

int main(void)
{
    struct Stack stack;
    StackInit(&stack);
    int i;
    for (i = 0; i < 5; i++)
    {
        StackPush(&stack, i);
    }

    while (!StackEmpty(&stack))
    {
        StackPop(&stack, &i);
        printf("%d ", i);
    }
    printf(" ");

    return 0;
}

C++实现：

 C++ Code 

#include <iostream>
using namespace std;

class Stack
{
private:
    struct Link
    {
        int data_;
        Link *next_;
        Link(int data, Link *next) : data_(data), next_(next)
        {

        }
    };

public:
    Stack() : head_(0), size_(0)
    {

    }

    ~Stack()
    {
        Link *tmp;
        while (head_)
        {
            tmp = head_;
            head_ = head_->next_;
            delete tmp;
        }
    }

    void Push(const int data)
    {
        Link *node = new Link(data, head_);
        head_ = node;
        ++size_;
    }

    bool Empty()
    {
        return (size_ == 0);
    }

    bool Pop(int &data)
    {
        if (Empty())
        {
            return false;
        }

        Link *tmp = head_;
        data = head_->data_;
        head_ = head_->next_;
        delete tmp;
        --size_;

        return true;
    }

private:
    Link *head_;
    int size_;
};

// 避免名称冲突
// 类型的扩充
// 数据封装、能够保护内部的数据结构不遭受外界破坏

int main(void)
{
    Stack stack;        // 抽象数据类型  类类型
    int i;
    for (i = 0; i < 5; i++)
    {
        stack.Push(i);      // this = &stack
    }

    while (!stack.Empty())
    {
        stack.Pop(i);
        cout << i << " ";
    }

    cout << endl;

    return 0;
}

输出都是一致的，对比不同的写法，可以体会两种语言的一些不同之处，当然这只是比较显而易见的方面了。

参考：

C++ primer 第四版
Effective C++ 3rd
C++编程规范