一个数组实现两个栈

要2个栈公用一个存储空间看来栈顶指针只能从两端开始了

设2个栈为栈1，栈2 ,栈1初始的栈顶指针为-1，栈2的初始栈顶指针为Size

#include<test.h>
class arraywithtwostack
{
public:
    arraywithtwostack(int size)
    {
        top[1] = -1;
        top[2] = size;
        array = new int[size + 1];
    }
    bool IsEmpty(int index);
    void Push(int index, int data);
    void Pop(int index);
    int top_data(int index);

private:
    int top[2];//   用来初始化-1 size
    int *array;
    int length; //数组的大小
};

#pragma once
#include"test.h"
#include<iostream>
#include<assert.h>
using namespace std;
bool arraywithtwostack::IsEmpty(int index)
{
    assert(index == 1 || index == 2);
    if (index == 1 && top[1] < 1)
    {
        return true;
    }
    if (index == 2 && top[2]>length)
    {
        return true;
    }
    return false;
}
void arraywithtwostack::Push(int index, int data)
{
    assert(index == 1 || index == 2);
    if (top[2] - top[1] == 1)
    {
        cout << "full" << endl;
        return;
    }
    else
    {
        index == 1 ? top[1]++ : top[2]--;
        array[top[index]] = data;
    }
}
void arraywithtwostack::Pop(int index)
{
    assert(index == 1 || index == 2);
    if (IsEmpty(index))
    {
        cout << "empty";
        return;
    }
    else
    {
        index == 1 ? top[1]-- : top[2]++;
    }
}
int arraywithtwostack::top_data(int index)
{
    assert(index == 1 ||  index== 2);
    if (IsEmpty(index))
    {
        cout << "empty" << endl;
        return -1;
    }
    return array[top[index]];
}
void main()
{
    arraywithtwostack s(5);
    s.Push(1, 5);
    s.Push(1, 6);
    cout<<s.top_data(1);
    system("pause");
}