Question

因此，我试图对基于数组的堆栈进行排序，但是我一直遇到以下问题：a.out（11849,0x115ce05c0）malloc： *对象0x7fc181402a80的错误：未分配释放的指针 a.out（11849,0x115ce05c0）malloc：* 在malloc_error_break中设置一个断点进行调试。这是我的课程说明

    StackType::StackType()
    {
        maxLength = 10;
        Top = -1;
        numArray = new int[maxLength];
    }

    //checks if stack is full
    bool StackType::isFull()
    {
        if(Top == maxLength -1)
            return true;
        else
            return false;
    }

    //checks if stack is empty
    bool StackType::isEmpty()
    {
        if(Top == -1)
            return true;
        else
            return false;
    }

    //insert numbers into stack
    void StackType::push(int num)
    {
        if(isFull())
            throw FullStack();

        Top++;
        numArray[Top] = num;
    }

    //deletes numbers in stack
    void StackType::pop()
    {
        if(isEmpty())
        throw EmptyStack();
        Top--;
    }

    //returns number at the top pf the stack
    int StackType::top()
    {
        if(isEmpty())
            throw EmptyStack();
        return numArray[Top];
    }

    //prints stack
    void StackType::printStack()
    {
        if(isEmpty())
            cout << "Stack is empty\n";
        else
        {
            int tempIndex = 0;
            //top is the last position of array
            cout << "Printing stack:\n";
            while(tempIndex <= Top)
            {
                cout << numArray[tempIndex] << endl;
                tempIndex++;
            }
        }
    }

    //deletes array
    StackType::~StackType()
    {
        delete [] numArray;
    }

这是我的客户代码

#include "StackType.h"
#include <iostream>
using namespace std;
StackType sortStack(StackType stack, StackType &tempStack);
int main ()
{
//read 10 ints into stack
//output them first
StackType currentStack, orderedStack;
currentStack.push(21);
currentStack.push(49);
currentStack.push(7);
currentStack.push(81);
currentStack.push(5);
currentStack.push(17);
currentStack.push(2);
currentStack.push(26);
currentStack.push(42);
currentStack.push(58);
currentStack.printStack();
cout << "The following is the sorted stack\n";
sortStack(currentStack, orderedStack);


//implement recursion here

//output stack again
return 0;
}
StackType sortStack(StackType stack, StackType &tempStack)
{
int current;
if(stack.isEmpty() && tempStack.isFull()) {
    cout << "did it \n";
    return tempStack;
}

else
{
    current = stack.top();
    stack.pop();
    if(tempStack.isEmpty())
    {
        cout << "here1 \n";
        tempStack.push(current);
        return sortStack(stack, tempStack);
    }
    else
    {
        if(current < tempStack.top())
        {
            stack.push(tempStack.top());
            tempStack.pop();
            tempStack.push(current);
            cout << "here2 \n";
            return sortStack(stack, tempStack);
        }
        else
        {
            //when current is greater than temp.top
            tempStack.push(current);
            cout << "here3 \n";
            return sortStack(stack, tempStack);


        }
    }
}
}

Answer 1

您按值传递StackType，这将导致它被复制，但是您没有提供复制构造函数。结果，您最终得到两个StackType实例，它们都指向同一数组，并且都试图删除它。第一个成功，另一个触发未定义的行为。

换句话说，您的课程违反了the Rule of Three/Five/Zero

使用递归对堆栈进行排序

1 个答案: