对双向链表进行排序会导致运行时错误

Question

void Sort()
{
    //bubble sort (ascending order)
    bool unsorted = true;
    while(unsorted)
    {
        unsorted = false;
        Node *currNode = this->head;
        //iterate through all the list
        while(currNode->next)
        {
            Node *nextNode = currNode->next;
            //if nextNode < currentNode, swap
            if(nextNode->data < currNode->data)
            {
                Node *temp = currNode->prev;
                currNode->next = nextNode->next;
                currNode->prev = nextNode;
                nextNode->next = currNode;
                nextNode->prev = temp;
                //if currentNode is head, new head points to next node
                if(currNode == this->head)
                {
                    this->head = nextNode;
                }
                //if nextnode is tail, new tail points to current node
                if(nextNode == this->tail)
                {
                    this->tail = currNode;
                }
                unsorted = true;
            }
            currNode = currNode->next;
        }
    }
}

I'm trying to sort doubly linkedlist using bubble sort, and I get a runtime error 'Process terminated with status -1073741819'. I'm not entirely sure if the two if-statements were necessarily inside the loop, but I thought it was necessary to keep track of head and tail of the linkedlist. So I think the issue is due to logical error, but I can't figure out where it went wrong.

Answer 1

You need to check for null pointer here:

Node *currNode = this->head;
while(currNode->next)

Everything else seems fine.

Also you need to run in debug mode in proper environment like VS if on Windows to see where the error actully is.