打印函数链表 C++

Question

我目前正在学习 C++ 中的链表，我无法编写打印列表元素的打印函数；我的意思是我写了这个函数，但它不能正常工作。

#include <iostream>

using namespace std;

struct node
{
    char name[20];
    node* next;
};

node* addNewPerson(node* head)
{
    node* person = new node;

    cout << "Name: ";
    cin >> person->name;

    person->next = NULL;

    if (head == NULL) //is empty
    {
        head = person;
    }

    else
    {
        person = person->next;
    }

    return head;
}

void printList(node* head)
{
    node* temp = head;

    cout << temp->name << endl;
}

int main()
{
    node* head = NULL;

    node* temp = head;

    unsigned short people = 0;

    cout << "How many people do you want to invite to the party?" << endl;
    cout << "Answer: ";
    cin >> people;

    cout << endl;

    for (unsigned short i = 1; i <= people; i++)
    {
        addNewPerson(head);

        cout << endl;
    }

    cout << "LIST: " << endl;
    cout << endl;

    while (temp != NULL)
    {
        printList(temp);
        temp = temp->next;
    }

    cin.get();
}

我想知道我做错了什么，请帮助我！

Answer 1

很明显，函数 addNewPerson 是错误的。

node* addNewPerson(node* head)
{
    node* person = new node;

    cout << "Name: ";
    cin >> person->name;

    person->next = NULL;

    if (head == NULL) //is empty
    {
        head = person;
    }

    else
    {
        person = person->next;
    }

    return head;
}

您分配了新的节点人员。

    node* person = new node;

将其字段设置为 NULL

    person->next = NULL;

然后，如果 head 不等于 NULL，则将 person 设置为 person->next

        person = person->next;

由于 person->next 被设置为 NULL，这意味着现在 person 也将等于 NULL。

此外，该函数返回可以在函数中更改的 head。但是你忽略了 main 中的返回值

addNewPerson(head);

至少应该有

head = addNewPerson(head);

有效函数 addNewPerson 可能如下所示

node* addNewPerson(node* head)
{
    node* person = new node;

    cout << "Name: ";
    cin >> person->name;

    person->next = head;
    head = person;

    return head;
}

主要你必须写

  for (unsigned short i = 1; i <= people; i++)
  {
    head = addNewPerson(head);

    cout << endl;
  }

函数 printList 不输出整个列表。它只输出首个节点的数据成员名称。

void printList(node* head)
{
    node* temp = head;

    cout << temp->name << endl;
}

它应该如下所示

void printList(node* head)
{
  for ( ; head; head = head->next )
  {
    cout << head->name << endl;
  }
}

最后主要应该看起来像

int main()
{
    node* head = NULL;

    unsigned short people = 0;

    cout << "How many people do you want to invite to the party?" << endl;
    cout << "Answer: ";
    cin >> people;

    cout << endl;

    for ( unsigned short i = 0; i < people; i++ )
    {
        head = addNewPerson(head);

        cout << endl;
    }

    cout << "LIST: " << endl;
    cout << endl;

    printList( head );

    cin.get();
}