在列表末尾插入一个整数，并在第n个位置删除

Inserting an integer at the end of the list and deleting at nth position

本文关键字：删除 位置 整数 列表 插入 一个      更新时间：2023-10-16

那么，在我的链表程序中，我想让它做的是询问用户要输入多少个数字，然后输入这些数字，并将这些数字加到列表的末尾。然后，它将打印列表。在此之后，用户将在列表中选择要删除的元素的位置，并再次打印列表。

#include <iostream>
using namespace std;
struct Node{
int data;
  Node* link;
};
Node* head;
void Insert(int data){ //insert an integer at the end of the list
  Node* temp = new Node();
  Node* temp2 = new Node();
  temp->data = data;
  temp->link = NULL;
  if(head = NULL){
    head = temp;
    return;
  }
  temp2 = head;
  while(temp2->link != NULL){
    temp2 = temp2->link;
  }
  temp2->link = temp;
}
void Delete(int n){ //delete an integer at nth position
  Node* temp1 = new Node();
  temp1 = head;
  if(n == 1){ //if the first node is to be deleted
    head = temp1->link; //now head points to second node
    delete temp1; //delete first node
    return;
  }
  for(int i = 0; i < n-2; i++){
    temp1 = temp1->link; //temp1 points to (n-1)th node
  }
  Node* temp2 = temp1->link; //temp2 points to nth node
  temp1->link = temp2->link; // pointing to (n+1)th node
  delete temp2; //deleting nth node
}
void Print(){ //print out the list
  Node* printNode = head;
  cout << "List: ";
  while(printNode != NULL){
    cout << printNode->data;
    cout << " ";
    printNode = printNode->link;
  }
  cout << "n";
}
int main(){
  int x, count, n;
  head = NULL; //start with an empty list
  cout << "How many numbers? " << endl;
  cin >> count;
  for(int i = 0; i < count; i++){
    cout << "Enter number: ";
    cin >> x;
    Insert(x);
  }
  Print();
  cout << "Enter position to delete: ";
  cin >> n;
  Delete(n);
  Print();
  return 0;
}

接受第一个数字后，程序停止工作。我能知道我在哪里做错了代码，我能做些什么使这段代码更有效?

我很惭愧，只是一个小错误。代码已更正。

if(head == NULL){
    head = temp;
    return;
}

您可能需要重新考虑您的插入函数。代码崩溃的部分是在插入while循环期间。如果您希望temp2保存数据，那么您需要动态地为它分配空间，您已经这样做了。然而，您只是将其用作位置指示器(遍历列表)-那么为什么您需要分配空间来指向列表中的头或任何其他节点位置呢?

下面是我插入列表的方法(当然是在后面): 
void Insert(int data){ //insert an integer at the end of the list
    Node* temp = new Node();
    // This is to ensure that temp was created -> Also called defensive programming.
    if (!temp)
   {
        cout << "We did not have enough space alloted to dynamically allocate a node!" << endl;
        exit(1);
    }
    temp->data = data; // Bad nominclature for program; Don't use the same name twice.
    temp->link = NULL;
    if (head == NULL)
    {
        head = temp;
    }
    else
    {
        // This is to help traverse the linked list without having to
        // manipulate the position of what head points to.
        Node *Pos_Indicator = head;
        while (Pos_Indicator->link != NULL)
        {
            Pos_Indicator = Pos_Indicator->link;
        }
        // We are at the end of the list, it is now safe to add.
        Pos_Indicator->link = temp;
        // Should probably have a check here for whether it was successful or not.
    }
}

我能够编译和运行你的代码完成，没有其他问题。让我知道这是否有帮助!

编辑:或者你知道(head = NULL)到(head == NULL)也可以:(

相关文章：