算法导论 简单顺序栈

简单顺序栈

1.什么是栈？什么是顺序栈？

栈是一种基本的数据结构，栈这种数据结构实现的是一种对元素进行后进先出（last-in, first-out,LIFO）的策略。栈的顺序存储结构称为顺序栈。顺序栈可以用一个一维数组和一个记录栈顶位置的整形变量来实现，数组用于顺序存储栈中所有的数据元素，栈顶指针用于存储栈顶元素的位置。

2.顺序栈的基本操作（伪代码）

STACK-EMPTY(S)

if S.top == 0
      return TRUE
else return FALSE

PUSH(S, x) //这里未考虑上溢

S.top = S.top + 1
S[S.top] = x

POP(S)

if STACK-EMPTY(S)
        error "underflow"
else S.top = S.top - 1
        return S[S.top + 1]

3.C++实现顺序栈的基本操作

//SequeStack.h
#pragma once

#include <assert.h>

template<typename ElemType>
class SequeStack
{
public:
    SequeStack(unsigned int size);
    bool Push(ElemType elem);
    bool Pop(ElemType* retElem);
    bool Empty() const;
    bool Visit(ElemType* elem, unsigned int pos) const;
private:
    ElemType* m_array;
    unsigned int m_top;
    unsigned int m_size;
};

template<typename ElemType>
bool SequeStack<ElemType>::Visit(ElemType* elem, unsigned int pos) const
{
    if (pos >= m_size || pos < 0)
    {
        assert(false && "Error: Visit Pos is out range of array!");
        return false;
    }
    *elem = m_array[pos];
    return true;
}

template<typename ElemType>
bool SequeStack<ElemType>::Empty() const
{
    if (m_top)
    {
        return false;
    }
    else
    {
        return true;
    }
}

template<typename ElemType>
bool SequeStack<ElemType>::Pop(ElemType* retElem)
{
    if (Empty())
    {
        assert(false && "Error: SequeStack is underflow!");
        return false;
    }
    else
    {
        *retElem = m_array[--m_top];
        return true;
    }
}

template<typename ElemType>
bool SequeStack<ElemType>::Push(ElemType pushElem)
{
    if (m_top == m_size)
    {
        assert(false && "Error: SequeStack is overflow!");
        return false;
    }
    else
    {
        m_array[m_top++] = pushElem;
        return true;
    }

}

template<typename ElemType>
SequeStack<ElemType>::SequeStack(unsigned int size)
    : m_array(new ElemType[size]),m_top(0),m_size(size)
{
    memset(m_array,0,sizeof(ElemType)*size);
}

//Util.h
#pragma once

namespace Util
{
    template<typename T>
    void PrintMemory(T& dateStruct, unsigned int size)
    {
        cout << "PrintMemory: ";
        for (int i = 0; i != size; i++)
        {
            ElemType tempElem;
            dateStruct.Visit(&tempElem,i);
            printf("%d ",tempElem);
        }
        printf("\n");
    }
}

//main.cpp
#include "SequeStack.h"
#include "Util.h"
#include <iostream>

using namespace std;

typedef int ElemType;

int main()
{
    const int STACK_SIZE = 10;
    SequeStack<ElemType> testSequeStack(STACK_SIZE);

    Util::PrintMemory(testSequeStack,STACK_SIZE);
    cout << (testSequeStack.Empty() ? "Empty SequeStack." : "Not Empty SequeStack.") << endl;

    for (int i = 1; i != 5; i++)
    {
        testSequeStack.Push(i);
        cout << "\nPush:" << i << endl;
        Util::PrintMemory(testSequeStack,STACK_SIZE);
        cout << (testSequeStack.Empty() ? "Empty SequeStack." : "Not Empty SequeStack.") << endl;
    }

    for(int i = 1; i!= 5; i++)
    {
        int temp;
        testSequeStack.Pop(&temp);
        cout << "\nPop:" << temp << endl;
        Util::PrintMemory(testSequeStack,STACK_SIZE);
        cout << (testSequeStack.Empty() ? "Empty SequeStack." : "Not Empty SequeStack.") << endl;
    }

    return 0;
}

4.运行结果

PrintMemory: 0 0 0 0 0 0 0 0 0 0

Empty SequeStack.


Push:1

PrintMemory: 1 0 0 0 0 0 0 0 0 0

Not Empty SequeStack.


Push:2

PrintMemory: 1 2 0 0 0 0 0 0 0 0

Not Empty SequeStack.


Push:3

PrintMemory: 1 2 3 0 0 0 0 0 0 0

Not Empty SequeStack.


Push:4

PrintMemory: 1 2 3 4 0 0 0 0 0 0

Not Empty SequeStack.


Pop:4

PrintMemory: 1 2 3 4 0 0 0 0 0 0

Not Empty SequeStack.


Pop:3

PrintMemory: 1 2 3 4 0 0 0 0 0 0

Not Empty SequeStack.


Pop:2

PrintMemory: 1 2 3 4 0 0 0 0 0 0

Not Empty SequeStack.


Pop:1

PrintMemory: 1 2 3 4 0 0 0 0 0 0

Empty SequeStack.