一个数组实现两个栈

图片讲解

代码实现

#define _CRT_SECURE_NO_WARNINGS 1
#include<iostream>
using namespace std;
#include <assert.h>
//一个数组实现两个栈（OneArrayToBothStack）
//自定义两个标记：i（i=1代表栈1，i=2代表栈2）

const int SizeStack = 20;//数组大小
template<class T>
class BothStack
{
public:
    BothStack() :count1(0), count2(0)
    {
        top1 = -1;
        top2 = SizeStack;
        //Capacity();
    }
    /*void Capacity()
    {
        if (count1 + count2 == SizeStack)
        {
            realloc（data, sizeof(int)*SizeStack * 2）;
        }
    }*/
    ~BothStack()
    {}

    void Push(int i, T x);//插入
    void Pop(int i);//删除
    T GetTop(int i);//得到栈顶元素
    bool Empty(int i);//判断栈是否为空
    void Print(int i);//先打印栈1，再打印栈2
    T Size(int i);//返回栈1/2的有效元素个数
protected:
    T data[SizeStack];
    int top1, top2;//top1标记的是栈1的栈顶；top2标记的是栈2的栈顶
    int count1, count2;//记录栈有效元素个数
};
template<class T>
void BothStack<T>::Push(int i, T x)
{
    if (top1 == top2 - 1)
    {
        throw "上溢";//该栈溢出（开辟的空间不够）
    }
    if (i == 1)
    {
        data[++top1] = x;
        ++count1;
    }
    else//if (i == 2)
    {
        data[--top2] = x;
        ++count2;
    }
}
template<class T>
void BothStack<T>::Pop(int i)
{
    if (i == 1)
    {
        //assert(top1 != -1);
        if (top1 == -1)
        {
            throw "下溢";//该top1栈内暂时没有存入元素
        }
        top1 =--top1;
        --count1;
    }
    else//if (i == 2)
    {
        //assert(top2 != SizeStack);
        if (top2 == SizeStack)
        {
            throw "下溢";//该top2栈内暂时没有存入元素
        }
        top2 = ++top2;
        --count2;
    }
}
template<class T>
T BothStack<T>::GetTop(int i)
{
    if (i == 1)
    {
        //assert(top1 != -1);
        if (top1 != -1)
        {
            return data[top1];
        }
    }
    else//if (i == 2)
    {
        //assert(top2!=SizeStack);
        if (top2 != SizeStack)
        {
            return data[top2];
        }
    }
    return -1;//栈内没有存入元素
}
template<class T>
T BothStack<T>::Size(int i)
{
    if (i == 1)
    {
        return count1;
    }
    else
    {
        return count2;
    }
}
template<class T>
bool BothStack<T>::Empty(int i)
{
    if (i == 1)
    {
        if (top1 == -1)
        {
            return true;
        }
        else
        {
            return false;
        }
    }
    else//if (i == 2)
    {
        if (top2 == SizeStack)
        {
            return true;
        }
        else
        {
            return false;
        }
    }
}
template <class T>
void BothStack<T>::Print(int i)
{
    if (i == 1)
    {
        assert(top1 != -1);
        int temp1 = top1;
        for (int i = 0; i < count1; ++i)
        {
            cout << data[temp1--]<<" ";
        }
        cout << endl;
    }
    else
    {
        assert(top2 != -1);
        int temp2 = top2;
        for (int i = 0; i < count2; ++i)
        {
            cout << data[temp2++] << " ";
        }
        cout << endl;
    }
}

void TestFun()
{
    BothStack<int> bs;

    bs.Push(1, 1);
    bs.Push(1, 2);
    bs.Push(1, 3);
    bs.Push(1, 4);
    bs.Push(1, 5);

    bs.Push(2, 6);
    bs.Push(2, 7);
    bs.Push(2, 8);
    bs.Push(2, 9);
    bs.Push(2, 10);
    bs.Push(2, 20);
    bs.Push(2, 30);
    cout << "栈1: ";
    bs.Print(1);
    cout << "栈2: ";
    bs.Print(2);

    cout <<"栈1有效元素："<<bs.Size(1)<<"  "<< "栈1顶元素：" << bs.GetTop(1) << endl;
    cout << "栈2有效元素：" << bs.Size(2)<<"  " << "栈2顶元素：" << bs.GetTop(2) << endl;

    bs.Pop(1);
    bs.Print(1);

    bs.Pop(2);
    bs.Print(2);
}
int main()
{
    TestFun();
    system("pause");
    return 0;
}

实现结果