C Program For Deleting A Node In A Linked List
Last Updated :
17 Aug, 2023
We have discussed Linked List Introduction and Linked List Insertion in previous posts on a singly linked list.
Let us formulate the problem statement to understand the deletion process. Given a ‘key’, delete the first occurrence of this key in the linked list.
Iterative Method:
To delete a node from the linked list, we need to do the following steps.
1) Find the previous node of the node to be deleted.
2) Change the next of the previous node.
3) Free memory for the node to be deleted.
Since every node of the linked list is dynamically allocated using malloc() in C, we need to call free() for freeing memory allocated for the node to be deleted.
C
#include <stdio.h>
#include <stdlib.h>
struct Node {
int data;
struct Node* next;
};
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;
}
void deleteNode( struct Node** head_ref, int key)
{
struct Node *temp = *head_ref, *prev;
if (temp != NULL && temp->data == key) {
*head_ref = temp->next;
free (temp);
return ;
}
while (temp != NULL && temp->data != key) {
prev = temp;
temp = temp->next;
}
if (temp == NULL)
return ;
prev->next = temp->next;
free (temp);
}
void printList( struct Node* node)
{
while (node != NULL) {
printf ( " %d " , node->data);
node = node->next;
}
}
int main()
{
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;
}
|
Output:
Created Linked List:
2 3 1 7
Linked List after Deletion of 1:
2 3 7
Time Complexity: O(n), where n represents the length of the given linked list.
Auxiliary Space: O(1), no extra space is required, so it is a constant.
Please refer complete article on Linked List | Set 3 (Deleting a node) for more details!
Like Article
Suggest improvement
Share your thoughts in the comments
Please Login to comment...