用于在给定位置删除链表节点的 C++ 程序

给定一个单链表和一个位置，删除给定位置的链表节点。

例子：

Input: position = 1, Linked List = 8->2->3->1->7
Output: Linked List =  8->3->1->7

Input: position = 0, Linked List = 8->2->3->1->7
Output: Linked List = 2->3->1->7

如果要删除的节点是根节点，直接删除即可。要删除中间节点，我们必须有一个指向要删除的节点之前的节点的指针。因此，如果位置不为零，我们运行一个循环位置 1 次并获得指向前一个节点的指针。

下面是上述思想的实现。

C++

// A complete working C++ program to delete
// a node in a linked list at a given position
#include 
using namespace std;
  
// A linked list node
class Node
{
    public:
    int data;
    Node *next;
};
  
// Given a reference (pointer to pointer) to 
// the head of a list and an int inserts a 
// new node on the front of the list. 
void push(Node** head_ref, int new_data)
{
    Node* new_node = new Node();
    new_node->data = new_data;
    new_node->next = (*head_ref);
    (*head_ref) = new_node;
}
  
// Given a reference (pointer to pointer) to
// the head of a list and a position, deletes
// the node at the given position 
void deleteNode(Node **head_ref, int position)
{
      
    // If linked list is empty
    if (*head_ref == NULL)
        return;
      
    // Store head node
    Node* temp = *head_ref;
  
    // If head needs to be removed
    if (position == 0)
    {
          
        // Change head
        *head_ref = temp->next; 
          
        // Free old head
        free(temp);             
        return;
    }
  
    // Find previous node of the node to be deleted
    for(int i = 0; temp != NULL && i < position - 1; i++)
        temp = temp->next;
  
    // If position is more than number of nodes
    if (temp == NULL || temp->next == NULL)
        return;
  
    // Node temp->next is the node to be deleted
    // Store pointer to the next of node to be deleted
     Node *next = temp->next->next;
  
    // Unlink the node from linked list
    free(temp->next); // Free memory
      
    // Unlink the deleted node from list
    temp->next = next; 
}
  
// This function prints contents of linked 
// list starting from the given node
void printList( Node *node)
{
    while (node != NULL)
    {
        cout << node->data << " ";
        node = node->next;
    }
}
  
// Driver code
int main()
{
      
    // Start with the empty list 
    Node* head = NULL;
  
    push(&head, 7);
    push(&head, 1);
    push(&head, 3);
    push(&head, 2);
    push(&head, 8);
  
    cout << "Created Linked List: ";
    printList(head);
    deleteNode(&head, 4);
    cout << "
Linked List after Deletion at position 4: ";
    printList(head);
    return 0;
}
  
// This code is contributed by premsai2030

输出：

Created Linked List: 
 8  2  3  1  7 
Linked List after Deletion at position 4: 
 8  2  3  1 

有关详细信息，请参阅有关在给定位置删除链接列表节点的完整文章！