鏈接列表析構函數崩潰C++程序

Question

我一直在研究我的析構函數，用於鏈接列表項目，其中偶數插入前面，奇數插入後面。取決於它是奇數還是偶數，刪除在最後進行中起作用。我有一切工作，但我運行我的析構函數時不斷收到錯誤。我已經完成了調試，它刪除了所有的節點，但之後崩潰，我不知道爲什麼。這裏是我的代碼：

//Headerfile 
class Staque 
{ 
private: 
struct staqueNode 
{ 
    int value; 
    struct staqueNode *next; 
    struct staqueNode *prev; 
}; 

staqueNode *root; 


public: 
Staque(); 
~Staque(); 

void addNode(int addIn); 
void deleteNode(int oddIn, int evenIn); 
void display(); 
}; 

//header.cpp file 
#include"Staque.h" 
#include<iostream> 

using namespace std; 

Staque::Staque() 
{ 
root = NULL;  
} 

void Staque::addNode(int addIn) 
{ 
staqueNode *newNode; 
staqueNode *nodePtr; 
staqueNode *temp = NULL; 

newNode = new staqueNode; 
newNode->value = addIn; 
newNode->next = NULL; 
newNode->prev = NULL; 
if (!root) 
{ 
    root = newNode; 
} 
else 
{ 
    if (newNode->value % 2 == 0) 
    { 
     nodePtr = root; 
     while (nodePtr->next) 
     { 
      nodePtr = nodePtr->next; 
     } 
     nodePtr->next = newNode; 
     newNode->prev = nodePtr; 
    } 
    else if (newNode->value % 2 != 0) 
    { 
     nodePtr = root; 
     while (nodePtr->prev) 
     { 
      nodePtr = nodePtr->prev; 
     } 
     nodePtr->prev = newNode; 
     newNode->next = nodePtr; 
    } 
} 
} 
void Staque::deleteNode(int oddIn, int evenIn) 
{ 
staqueNode *nodePtr; 
staqueNode *temp = NULL; 
if (!root) 
    return; 
while (evenIn > 0) 
{ 
    nodePtr = root; 
    while (nodePtr != NULL && nodePtr->next != NULL) 
    { 
     temp = nodePtr; 
     nodePtr = nodePtr->next; 
    } 
    if (nodePtr == root && root->value % 2 == 0) 
    { 
     root = root->prev; 
     temp->next = NULL; 
     delete nodePtr; 
     evenIn = 0; 
    } 
    else 
    { 
     temp->next = NULL; 
     delete nodePtr; 
     evenIn -= 1; 
    } 
} 

while (oddIn > 0) 
{ 
    nodePtr = root; 
    while (nodePtr != NULL && nodePtr->prev != NULL) 
    { 
     temp = nodePtr; 
     nodePtr = nodePtr->prev; 
    } 
    if (nodePtr == root && root->value % 2 != 0) 
    { 
     root = root->next; 
     temp->prev = NULL; 
     delete nodePtr; 
     oddIn = 0; 
    } 
    else 
    { 
     temp->prev = NULL; 
     delete nodePtr; 
     oddIn -= 1; 
    } 
} 

} 

void Staque::display() 
{ 
staqueNode *nodePtr; 

nodePtr = root; 
while (nodePtr->next) 
{ 
    nodePtr = nodePtr->next; 
} 
cout << "\nThe staque: "; 
while (nodePtr->prev) 
{ 
    cout << nodePtr->value << " "; 
    nodePtr = nodePtr->prev; 
} 
cout << nodePtr->value << endl; 

} 

Staque::~Staque() 
{ 
staqueNode *nodePtr; 
staqueNode *temp; 
nodePtr = root; 

while (nodePtr->next) 
{ 
    temp = nodePtr; 
    nodePtr = nodePtr->next; 
} 
//nodePtr = root; 
while (nodePtr->prev) 
{ 
    temp = nodePtr; 
    nodePtr = nodePtr->prev; 
    delete temp; 
} 
//delete root; 

} 


//source/main.cpp 
#include"Staque.h" 
#include<iostream> 


using namespace std; 

int main() 
{ 
Staque myList; 
int choice; 
int input; 
int numOdd; 
int numEven; 

do 
{ 
    cout << "Would you like to: \nAdd a node: 1\nDelete a node: 2\nDisplay the list: 3\nQuit: 0\n"; 
    cin >> choice; 
    while (choice < 0 || choice > 3) 
    { 
     cout << "Invalid Input: Would you like to: \nAdd a node: 1\nDelete a node: 2\nDisplay the list: 3\nQuit: 0\n"; 
     cin >> choice; 
    } 
    switch (choice) 
    { 
    case 1: 
     cout << "Enter the value you would like to add to the list: "; 
     cin >> input; 
     while (isalpha(input)) 
     { 
      cout << "Invalid input: Enter the value you would like to add to the list: "; 
      cin >> input; 
     } 
     myList.addNode(input); 
     myList.display(); 
     break; 

    case 2: 
     cout << "Enter the number of even numbers you would like to delete: "; 
     cin >> numEven; 
     while (isalpha(input) || numEven < 0) 
     { 
      cout << "Invalid input: Enter the number of even numbers you would like to delete: "; 
      cin >> numEven; 
     } 

     cout << "Enter the number of odd numbers you would like to delete: "; 
     cin >> numOdd; 
     while (isalpha(input) || numEven < 0) 
     { 
      cout << "Invalid input: Enter the number of odd numbers you would like to delete: "; 
      cin >> numOdd; 
     } 
     myList.deleteNode(numOdd, numEven); 
     myList.display(); 
     break; 

    case 3: 
     myList.display(); 
     break; 

    default: 
     break; 

    } 
} while (choice != 0); 

myList.~Staque(); 

return 0; 

} 

Answer 1

一個明顯的錯誤是你明確地調用你的析構函數。

myList.~Staque(); 

您不應該這麼做 - 當物體超出範圍時，物體將自然「死亡」。通過顯式調用析構函數，對象將調用析構函數，然後當對象超出範圍時，析構函數將被第二次調用。這是第二次調用會導致所有的破壞。

您應該明確調用析構函數的時間是如果您使用placement-new，並且您在此沒有這樣做。因此，只需刪除上面的那一行，看看錯誤是否消失。如果沒有，那麼你還有其他問題，但至少你會從代碼中刪除這個明顯的問題。

Answer 2

看你的析構函數特別...

時NODEPTR爲空，會發生什麼？例如你沒有創建一個節點。

或者你到達最後一個總是將下一個ptr設置爲NULL的節點，然後在空指針上解引用nodePtr-> next - 是的，你猜它是一個崩潰。

你的while（nodePtr-> next）什麼是臨時任務在做什麼？看起來沒有用。

while（nodePtr-> prev）???

不檢查nodePtr爲空嗎？

多數民衆贊成開始。

你確定它的其餘部分工作？