用于删除链表中节点的 C 程序

我们在之前关于单链表的文章中讨论了链表介绍和链表插入。
让我们制定问题陈述以了解删除过程。给定一个“键”，删除链表中该键的第一次出现。

迭代方法：
要从链表中删除一个节点，我们需要执行以下步骤。
1）找到要删除的节点的前一个节点。
2）改变前一个节点的下一个。
3) 为要删除的节点释放内存。

由于链表的每个节点都是使用 C 中的 malloc() 动态分配的，因此我们需要调用 free() 来释放为要删除的节点分配的内存。

C

// A complete working C program
// to demonstrate deletion in
// singly linked list
#include 
#include 
  
// A linked list node
struct Node {
    int data;
    struct 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(struct Node** head_ref, int new_data)
{
    struct Node* new_node
        = (struct Node*)malloc(sizeof(struct 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 key, deletes the first occurrence of key in
   linked list */
void deleteNode(struct Node** head_ref, int key)
{
    // Store head node
    struct Node *temp = *head_ref, *prev;
  
    // If head node itself holds the key to be deleted
    if (temp != NULL && temp->data == key) {
        *head_ref = temp->next; // Changed head
        free(temp); // free old head
        return;
    }
  
    // Search for the key to be deleted, keep track of the
    // previous node as we need to change 'prev->next'
    while (temp != NULL && temp->data != key) {
        prev = temp;
        temp = temp->next;
    }
  
    // If key was not present in linked list
    if (temp == NULL)
        return;
  
    // Unlink the node from linked list
    prev->next = temp->next;
  
    free(temp); // Free memory
}
  
// This function prints contents of linked list starting
// from the given node
void printList(struct Node* node)
{
    while (node != NULL) {
        printf(" %d ", node->data);
        node = node->next;
    }
}
  
// Driver code
int main()
{
    /* Start with the empty list */
    struct Node* head = NULL;
  
    push(&head, 7);
    push(&head, 1);
    push(&head, 3);
    push(&head, 2);
  
    puts("Created Linked List: ");
    printList(head);
    deleteNode(&head, 1);
    puts("
Linked List after Deletion of 1: ");
    printList(head);
    return 0;
}

输出：

Created Linked List: 
 2  3  1  7 
Linked List after Deletion of 1: 
 2  3  7

请参阅链表上的完整文章 |设置 3（删除节点）了解更多详情！