【发布时间】：2020-02-11 12:37:49
【问题描述】：
我面临一个问题，我似乎无法找到特定节点，然后从链接列表中删除该节点。我试图创建最后显示的while循环，循环两次包含节点的head的内存分配，然后删除它，但如果我将deleteNode设置为2，它似乎会删除两个节点。
void delete_list(Book *&head, Book *&last){
if (head == NULL)
{
cout << "Database is already empty! \n";
}
else if (head == last){
delete head;
head = NULL;
last = NULL;
}
else
{
cout << "Please enter the number of the node you would like to delete \n";
cin >> deleteNode;
Book* new_book = head;
while(deleteNode>0) {
head = head -> next;
deleteNode--;
}
delete new_book;
}
}
#include <iostream>
#include <string>
using namespace std;
struct Book{
string title;
string author;
string publisher;
int publishYear;
int isbn;
Book* next;
};
void add_node(Book*&, Book*&);
void print_list(Book*);
void delete_list(Book*& , Book*& );
int deleteNode;
int main()
{
Book* head = NULL;
Book* last = NULL;
char option;
do{
cout << "Press required option: \n" "To Add Book detail [A]\n"
"To Print Book details [P]\n" "To Delete Book details [D]\n"
"Quit [Q]\n";
cin >> option;
switch(option){
case 'A':
add_node(head, last);
break;
case 'P':
print_list(head);
break;
case 'D':
delete_list(head, last);
case 'Q':
break;
default:
cout << "Invalid Input" << endl;
}
} while (option != 'Q');
return 0;
}
void add_node(Book *&head, Book *&last){
//Cheaks the empty link list
if (head == NULL){
Book* new_book = new Book();
cout <<"Enter Book name \n";
cin >> new_book -> title;
cout << "Enter author name \n";
cin >> new_book -> author;
cout << "Enter publisher name \n";
cin >> new_book -> publisher;
cout << "Enter publish year \n";
cin >> new_book -> publishYear;
cout << "Enter ISBN number \n";
cin >> new_book -> isbn;
new_book -> next = NULL;
head = new_book;
last = new_book;
}
else
{
Book* new_book1 = new Book;
cout <<"Enter Book name \n";
cin >> new_book1 -> title;
cout << "Enter author name \n";
cin >> new_book1 -> author;
cout << "Enter publisher name \n";
cin >> new_book1 -> publisher;
cout << "Enter publish year \n";
cin >> new_book1 -> publishYear;
cout << "Enter ISBN number \n";
cin >> new_book1 -> isbn;
last -> next = new_book1;
last = new_book1;
}
}
void print_list(Book* in_root){
Book* next_ptr;
next_ptr = in_root;
if(next_ptr == NULL)
{
cout << "No information found! \n";
}
else
{
while (next_ptr != NULL){
cout << "Book Name: "<<next_ptr -> title << endl;
cout << "Author Name: "<<next_ptr -> author << endl;
cout << "Publisher: "<<next_ptr -> publisher << endl;
cout << "Publishing Year: "<<next_ptr -> publishYear << endl;
cout << "ISBN Number: "<<next_ptr -> isbn << endl;
cout << " \n";
next_ptr = next_ptr -> next;
}
}
}
void delete_list(Book *&head, Book *&last){
if (head == NULL)
{
cout << "Database is already empty! \n";
}
else if (head == last){
delete head;
head = NULL;
last = NULL;
}
else
{
cout << "Please enter the number of the node you would like to delete \n";
cin >> deleteNode;
Book* new_book = head;
while(deleteNode>0){
head = head -> next;
deleteNode--;
}
delete new_book;
}
}
【问题讨论】：
-
请为我们提供完整的工作示例，以便我们轻松测试。
-
我喜欢函数参数是引用指针
-
@NutCracker 我已经提供了完整的代码。它应该是一个程序，将书籍信息存储在节点的动态内存中，用户可以删除特定书籍及其所有信息
-
删除单链表中的 any 节点涉及一件事：找到指向该节点的指针并从列表中删除该节点。该指针可以是 (a)
head指针，或 (b) 某个其他节点中的某个next指针。没有其他选择。并且仅供参考，当使用指针指向实际列表时，这更容易（恕我直言）。
标签： c++ pointers dynamic linked-list structure