c++ Stack Array实现及显示错误

如何解决c++ Stack Array实现及显示错误

因此，在我的作业中，我们应该创建一个 Stack 类，该类使用数组实现为 double 类型的值创建堆栈。

这是头文件：

#ifndef STACK_H
#define STACK_H

class Stack
{
    private:
        double *stackArray;             //Pointer to the Stack array.
        int stackSize;                  //The size of stack.
        int top;                        //The first "plate" on top of the stack/Holds the index of the first element in the stack
        
        void copy(const Stack &copy);  //The fxn the copy constructor calls. 
        void destroy();                 //The fxn the destructor calls.
        void resize();                  //Makes the array larger if capacity has been reached.
        
    public:
        Stack();                    //Default Constructor
        /***
        Stack(const Stack&);            //Copy Constructor 
        ***/
        
        ~Stack();                          //Destructor 
        
        
        //STACK OPERATIONS:
        void push(double);              //Adds a 'plate' on top of the stack. 
        
        void pop();             //Removes 'plate' on top of stack. 
        
        bool isEmpty();           //Returns true if stack is empty,false otherwise.
        
        bool isFull();            //Returns true if stack is full,false otherwise.
        
        double peek();                  //Gets the top item of the stack without removing the item. 
        
        int getSize();                  //Makes the array larger if the capacity of the array is being reached. 
        
        void display() const;  //Displays the values in the stack.
};
#endif 

这是实现文件：

#include "Stack.h"
#include <iostream>
using namespace std;


Stack::Stack()                    //The Constructor 
{
    stackSize = 1;
    stackArray = new double[stackSize];       //Dynamically allocate memory for an array of a stack variable.
    top = -1;                           //Set the top of the stack to -1. So its empty.
}

/***
Stack::Stack(const Stack &obj)                     //The Copy constructor 
{
    copy(const Stack &copy);
}
***/


Stack::~Stack()                         //The destructor 
{
    destroy();                          //Calls the destroy function to delete the array.
}




void Stack::push(double value)          //Adds a new 'plate' on the stack 
{
    if (isFull())
    {
        resize();                       //Makes a new stack that is double the size of the current one 
                                       //While copying all values of the previous stack.
        push(value);
    }
    
    top++;                                  //Increment top....
    stackArray[top] = value;                //...So we can make 'value' the new top in the array.
}


void Stack::pop()                 //Removes a 'plate' from the stack 
{
    if (isEmpty())
    {
        cout << "The stack is empty.\n";
    }
    else                                        //Otherwise...
    {
        top--;                                  //Removes the current value of top from the stack. 
    }
}


bool Stack::isEmpty() 
{
    bool status;                        //Tells the current status of the stack
    
    if (top == -1)                           //If theres nothing in the stack...
    {
        status = true;                 //...status returns true. 
    }
    else                              //Otherwise...
    {
        status = false;              //...The stack MUST have something already in it.
    }
    
    return status;                  
}


bool Stack::isFull() 
{
    bool status;                    
    
    if (top == stackSize - 1)               //Checks if the top of the stack is equal to the max stack size entered.
        status = true;                      //Returns true if stack is full.
    else
        status = false;                     //Or false if not.
    
    return status;          
}


void Stack::destroy()
{
    delete [] stackArray;           //Delete the Stack Array.
}


double Stack::peek()            //Gets the top item of the stack without removing item 
{
    return stackArray[top];
}


int Stack::getSize()                                        //Determines the size of the stack
{
    return top + 1;
}


void Stack::resize()
{
    
    stackSize *= 2;                                         //Make the stackSize of the new array 
                                                            //AT LEAST TWICE as big as the previous one. 

   double *stackArray2nd = new double[stackSize];                     //Make new array
    
    for (int index = 0; index <= top; index++)
    {
        stackArray2nd[index] = stackArray[index];          //Make the new stack array equal to the old stack array.
    }
    
    destroy();
    stackArray = stackArray2nd;                         //Stack array no longer has a size associated with it 
}




void Stack::copy(const Stack &copy)    
{
    stackSize = copy.stackSize;                         //Copy the stackSize attribute.
    
    for (int index = 0; index < stackSize; index++)    //Copy the Stack's contents 
        stackArray[index] = copy.stackArray[index];    
        
    top = copy.top;                                   //Set the top of the stack.
}


void Stack::display() const                       //Prints out the stack 
{
    for (int index = 0; index <= top; index++)
    {
        cout << stackArray[index] << " ";
    }
    cout << endl;
}

这是驱动程序：

#include <iostream>
#include "Stack.h"
using namespace std;

int main()
{
    
    Stack stack1;
    
    cout << "Lets get the stack size!\n";           //Check to see if the getSize function works 
    cout << stack1.getSize();
    
    cout << "\nLets see if we can add a value on to the stack!\n";
    stack1.push(33.2);
    stack1.display();
    
    cout << "\nLets add another.\n";
    stack1.push(27.4);
    stack1.display();

    return 0;
}

我的问题是，当我尝试运行它时，它会编译，但由于某种原因，我得到了这个：

Lets get the stack size!
0
Lets see if we can add a value to the stack!
33.2

Lets add another.
33.2 27.4 27.4

为什么要添加另一个 27.4？还有一个问题，我似乎无法将推入数组的值作为最左侧的第一个值打印出来。

请帮忙！我不确定为什么会发生这种情况。