在 C++ 的链表中添加新节点时程序崩溃

Question

我正在尝试实现链接的插入功能，但一旦我添加第三个元素，程序就会崩溃并停止执行，即使相同的代码在 hackerrank 的编译器上工作也是如此。

这是我的代码。

#include<bits/stdc++.h>
using namespace std;

class Node{
    public:
        int data;
        Node * next;
        Node(int data){
            this -> data = data;
            this -> next = nullptr;
        }
};

Node * insert_tail(Node * head, int data){
    Node * node = new Node(data);
    if(head == nullptr) return node;
    Node * current = head;
    while(head -> next != nullptr) current = current -> next;
    current -> next = node;
    return head;
}

void print_linkedlist(Node * head){
    while(head -> next != nullptr){
        cout << head -> data << " -> ";
        head = head -> next;
    }
    cout << head -> data << " -> nullptr";
}

int main(){
    Node *  head = nullptr;
    head = insert_tail(head, 1);
    head = insert_tail(head, 5);
    head = insert_tail(head, 3);
    head = insert_tail(head, 5);
    head = insert_tail(head, 8);
    head = insert_tail(head, 17);

    print_linkedlist(head);
    return 0;
}

Answer 1

行

    while(head -> next != nullptr) current = current -> next;

函数中的insert_tail是错误的。当 head->next 不是 nullptr.

时，它将无休止地运行

应该是

    while(current -> next != nullptr) current = current -> next;

Answer 2

这里有错字

while(head -> next != nullptr) current = current -> next;
      ^^^^^^^^^^^^

写

while(current -> next != nullptr) current = current -> next;
      ^^^^^^^^^^^^

函数的另一种定义如下所示，

void insert_tail( Node * &head, int data )
{
    Node **current = &head;

    while ( *current ) current = &( *current )->next;

    *current = new Node( data );
}

并且可以像

一样简单地调用该函数

insert_tail(head, 1);

函数print_linkedlist也可以写成

std::ostream & print_linkedlist( const Node * head, std::ostream &os = std::cout )
{
    for ( ; head; head = head->next )
    {
        os << head -> data << " -> ";
    }

    return os << "nullptr";
}

可以这样称呼

print_linkedlist(head) << '\n';

在 C++ 的链表中添加新节点时程序崩溃

Program crashes while adding a new node in linked list in c++

c++

class

linked-list

data-structures

singly-linked-list