链表实现中的错误

Question

The following is an excerpt from the code to a singly linked list implementation from Data Structures and Algorithms in C++ (2nd Edition) by Adam Drozdek that involves deleting a node with a given value.

IntNode *tmp = head->next;
head = head->next;
delete tmp;

( head is defined elsewhere as an IntNode*) Are there typos in this code fragment, or is my mental processor incorrect in that head will always be a null pointer after every execution of the above code fragment?

Answer 1

不，它将指向列表的第二个元素（现在是第一个）。

Answer 2

When you write delete tmp , you are deleting the object pointed to by tmp . However, after deleting head will still point to the same place. Dereferencing it ( *head ) will cause problems, because the object head is pointing to has been deleted.