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g ++を使用してLinuxボックスでコードをコンパイルでき、ドライバを正常に実行できます。私のWindowsマシン上でドライバをコンパイルして実行すると、メソッドのptr->nextステートメントで読み取りアクセス違反エラーが発生します。 （ノードが1つしかないと仮定して）デバッグ中は、whileステートメントを1回ステップ実行し、2回目のパスではノードがなくてもptr != nullptrを継続します。C++ Visual Studioの二重リンクリストの読み取りアクセス違反
このエラーは、ノードとリストsize == 1を追加するときに発生します。
私はすべての声明を見ていて、私が間違っていた場所を見つけることができないようです。これに関するすべての情報をいただければ幸いです！
ヘッダー
#ifndef DEQUE_H
#define DEQUE_H
#include <iostream>
using namespace std;
template <class Object>
class Deque {
public:
Deque(); // the constructor
Deque(const Deque &rhs); // the copy constructor
~Deque(); // the destructor
bool isEmpty() const; // checks if a deque is empty.
int size() const; // retrieves # deque nodes
const Object &getFront() const; // retrieve the front node
const Object &getBack() const; // retrieve the tail node
void clear(); // clean up all deque entries.
void addFront(const Object &obj); // add a new node to the front
void addBack(const Object &obj); // add a new node to the tail
Object removeFront(); // remove the front node
Object removeBack(); // remove the tail node
const Deque &operator=(const Deque &rhs); // assignment
private:
struct DequeNode { // a deque node
Object item;
DequeNode *next;
DequeNode *prev;
};
DequeNode *front;
DequeNode *back;
};
#include "deque.cpp.h"
#endif
CPP
template <class Object>
Deque<Object>::Deque() { // the constructor
front = back = NULL;
}
template <class Object>
Deque<Object>::Deque(const Deque &rhs) { // the copy constructor
front = back = NULL;
*this = rhs;
}
template <class Object>
Deque<Object>::~Deque() { // the destructor
clear();
}
template <class Object>
bool Deque<Object>::isEmpty() const { // check if a deque is empty
return front == NULL;
}
template <class Object>
int Deque<Object>::size() const { // retrieves # deque nodes
int length = 0;
DequeNode* ptr = front;
while (ptr != nullptr) {
length++;
ptr = ptr->next;
}
return length;
}
template <class Object>
const Object &Deque<Object>::getFront() const { // retrieve the front node
if (isEmpty())
throw "empty queue";
return front->item;
}
template <class Object>
const Object &Deque<Object>::getBack() const { // retrieve the tail node
if (isEmpty())
throw "empty queue";
return back->item;
}
template <class Object>
void Deque<Object>::clear() { // clean up all entries.
while (!isEmpty()) // dequeue till the queue gets empty.
removeFront();
}
template <class Object>
void Deque<Object>::addFront(const Object &obj) {// add a new node to front
// Implement the function body.
DequeNode* newNode = new DequeNode;
newNode->item = obj;
// if no nodes, new node is front and back
if (isEmpty()){
front = back = newNode;
}
// if one node, new front and back are established
else if (size() == 1){
back->prev = newNode;
front = newNode;
front->next = back;
}
// add to front and shift right
else {
DequeNode* oldFront = front;
front->prev = newNode;
front = newNode;
front->next = oldFront;
}
}
template <class Object>
void Deque<Object>::addBack(const Object &obj) { // add a new node to tail
// Implement the function body.
DequeNode* newNode = new DequeNode;
newNode->item = obj;
// if no nodes, new node is front and back
if (isEmpty()){
front = back = newNode;
}
// if one node, new front and back are established
else if (size() == 1){
front->next = newNode;
back = newNode;
back->prev = front;
}
// add to back and shift left
else {
DequeNode* oldBack = back;
back->next = newNode;
back = newNode;
back->prev = oldBack;
}
}
template <class Object>
Object Deque<Object>::removeFront() { // remove the front node
// Implement the function body.
if (isEmpty())
throw "empty queue";
// if only one node, return item, Deque is now NULL.
else if (size() == 1){
DequeNode* remove = front;
Object result = remove->item;
front = back = NULL;
delete remove;
remove = NULL;
return result;
}
// remove front node, shift right
else {
Object result = front->item;
DequeNode* remove = front;
front = front->next;
front->prev = NULL;
delete remove;
remove = NULL;
return result;
}
}
template <class Object>
Object Deque<Object>::removeBack() { // remove the tail node
// Implement the function body.
if (isEmpty())
throw "empty queue";
// if only one node, return item, Deque is now NULL.
else if (size() == 1){
DequeNode* remove = back;
Object result = remove->item;
front = back = NULL;
delete remove;
remove = NULL;
return result;
}
// remove back node, shift left
else {
Object result = back->item;
DequeNode* remove = back;
back = back->prev;
back->next = NULL;
delete remove;
remove = NULL;
return result;
}
}
template <class Object>
const Deque<Object> &Deque<Object>::operator=(const Deque &rhs) { // assign
if (this != &rhs) { // avoid self assignment
clear();
for (DequeNode *rptr = rhs.front; rptr != NULL; rptr = rptr->next)
addBack(rptr->item);
}
return *this;
}
ドライバー
#include <iostream>
#include "deque.h"
using namespace std;
int main() {
Deque<int> deque1;
int item;
for (int j = 0; j < 5; j++)
deque1.addBack(j);
for (int j = 5; j < 10; j++)
deque1.addFront(j);
Deque<int> deque2 = deque1;
deque2.addBack(10);
cout << "deque1: " << endl;
while (!deque1.isEmpty())
cout << deque1.removeFront() << endl;
cout << "deque2: " << endl;
while (!deque2.isEmpty())
cout << deque2.removeBack() << endl;
}
'nullptr'はC++ 11標準です。 WindowsコンパイラはC++ 11を実装していますか？ –