【數據結構】34_棧的概念及實現（上）

時間 2020-01-18

標籤數據結構概念實現欄目數據結構简体版

原文原文鏈接

棧的定義

棧是一種特殊的線性表

棧僅能在線性表的一端進行操做ios

棧頂（Top）:容許操做的一端

棧底（Bottom）:不容許操做的一端

棧的特性

後進先出 (Last In first Out)

棧的操做

建立棧 (Stack())

銷燬棧 (~Stack())

清空棧 (clear())

進棧 (push())

出棧 (pop())

獲取棧頂元素 (top())

獲取棧大小 (size())

棧的實現

template <typename T>
class Stack : Object
{
public:
    virtual void push(const T &e) = 0;
    virtual void pop() = 0;
    virtual T top() const = 0;
    virtual void clear() = 0;
    virtual int size() const = 0;
};

棧的順序實現

StaticStack 設計要點

類模板編程

使用原生數組做爲棧的存儲空間

使用模板參數決定棧的最大容量

template <typename T, int N>
class StaticStack : public Stack<T>
{
public:
    StaticStack();          // 初始化成員變量
    int capacity() const;  
protected:
    T m_space[N];           // 棧存儲空間，N爲模板參數
    int m_top;              // 棧頂標識
    int m_size;             // 當前棧的大小
};

編程實驗：基於順序存儲結構的棧

文件：Stack.h數組

#ifndef STACK_H
#define STACK_H

#include "Object.h"

namespace DTLib
{

template <typename T>
class Stack : public Object
{
public:
    virtual void push(const T &e) = 0;
    virtual void pop() = 0;
    virtual T top() const = 0;
    virtual void clear() = 0;
    virtual int size() const = 0;
};

}

#endif // STACK_H

文件：StaticStack.hide

#ifndef STAITCSTACK_H
#define STAITCSTACK_H

#include "Stack.h"
#include "Exception.h"

namespace DTLib
{

template <typename T, int N>
class StaticStack : public Stack<T>
{
public:
    StaticStack() = default;

    int capacity() const  // O(1)
    {
        return N;
    }

    void push(const T &e) override  // O(1)
    {
        if (m_size < N)
        {
            m_space[m_top + 1] = e;

            ++m_top;
            ++m_size;
        }
        else
        {
            THROW_EXCEPTION(InvalidOpertionExcetion, "No enough space to push StaticStack ...");
        }
    }

    void pop() override  // O(1)
    {
        if (m_size > 0)
        {
            --m_top;
            --m_size;
        }
        else
        {
            THROW_EXCEPTION(InvalidOpertionExcetion, "No element to pop StaticStack ...");
        }
    }

    T top() const override  // O(1)
    {
        if (m_size > 0)
        {
            return m_space[m_top];
        }
        else
        {
            THROW_EXCEPTION(InvalidOpertionExcetion, "No element in current StaticStack ...");
        }
    }

    void clear() override  // O(1)
    {
        m_top = -1;
        m_size = 0;
    }

    int size() const override  // O(1)
    {
        return m_size;
    }

    ~StaticStack()  // O(1)
    {
        clear();
    }

protected:
    T m_space[N];
    int m_top = -1;
    int m_size = 0;
};

}

#endif // STAITCSTACK_H

文件：main.cppspa

#include <iostream>
#include "StaitcStack.h"

using namespace std;
using namespace DTLib;

int main()
{
    StaticStack<int, 5> stack;

    for (int i=0; i<5; ++i)
    {
        stack.push(i);
    }

    while (stack.size() > 0)
    {
        cout << stack.top() << endl;
        stack.pop();
    }

    return 0;
}

輸出：設計