Question

我有这个C ++链接列表程序。该函数不调用insertAsFirstElement（）

不知道为什么？

我在codeblocks中运行这个程序。

我从youtube获得了这个程序，上传者正在使用visual studio来完成这个程序。

我无法解决此问题，如果程序不正确，请在发现任何错误的地方进行更改。

感谢。

 #include <iostream>
 using namespace std;

 struct node
 {
 int number;
 node *next;
 };

 bool isEmpty(node *head);
 char menu();
 void insertAsFirstElement(node *&head, node *&last, int number);
 void insert(node *&head, node *&last, int number);
 void remove(node *&head, node *&last);
 void showList(node *current);


 bool isEmpty(node *head)
 {
 if (head == NULL)
 return true;
 else
 return false;
 }
char menu()
{
char choice;
cout << "Menu\n";
cout << "1. Add an item.\n";
cout << "2. Remove an item.\n";
cout << "3. Show an item.\n";
cout << "4. Exit\n";

cin >> choice;
return choice;

  }
  void insertAsFirstElement(node *&head, node *&last, int number)
{
node *temp = new node;
temp->number = number;
temp->next = NULL;
head = temp;
last = temp;
 }
 void insert(node *&head, node *&last, int number)
{
if(isEmpty(head))
{
    insertAsFirstElement(head,last,number);
    cout << "Hello I am here!!\n";
}

else
{
    node *temp = new node;
    temp->number = number;
    temp->next = NULL;
    last->next = temp;
    last = temp;
}
 }
  void remove(node *&head, node *&last)
   {
  if(isEmpty(head))
     cout << "The list is already empty.\n";
  else if (head == last)
     {
       delete head;
       head == NULL;
       last == NULL;
      }
  else
     {
       node *temp = head;
       head = head->next;
       delete temp;
      }
 }
  void showList(node *current)
  {
   if(isEmpty(current))
     cout << "The list is empty\n";
   else
    {
      cout << "The List contains:\n";
       while(current != NULL)
        {
            cout << current->number << endl;
            current = current->next;
         }
      }
  }

 int main()
 {
node *head = NULL;
node *last = NULL;

char choice;
int number;

choice = menu();
cout<< choice;
do {

    switch(choice)
          {
            case '1': cout << "Please Enter the number:";
            cin >> number;
            insert(head,last,number);
            break;
            case '2': cout << "Will Remove the number:" ;
            remove(head,last);
            break;
            case '3' : cout << "Showing The Linked List:\n";
            showList(head);
            break;
            default: cout << "System exit\n";
          }
}while ( choice != '4');

return 0;

 }

Answer 1

你的行为... while循环需要不断询问用户的选择，这里有一个改变：

do {
choice = menu();
cout<< choice;
    switch(choice)
          {
            case '1': cout << "Please Enter the number:";
            cin >> number;
            insert(head,last,number);
            break;
            case '2': cout << "Will Remove the number:" ;
            remove(head,last);
            break;
            case '3' : cout << "Showing The Linked List:\n";
            showList(head);
            break;
            default: cout << "System exit\n";
          }
}while ( choice != '4');

希望有所帮助

不调用C ++链表程序函数

1 个答案: