Created
February 20, 2017 13:32
-
-
Save zjplab/7851de2ccd9e12c850b834455706adbc to your computer and use it in GitHub Desktop.
Deleting a node in a linkedlist
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
// A complete working C program to demonstrate deletion in singly | |
// linked list | |
#include <stdio.h> | |
#include <stdlib.h> | |
// 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; | |
} | |
} | |
/* Drier program to test above functions*/ | |
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("\nLinked List after Deletion of 1: "); | |
printList(head); | |
return 0; | |
} |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
# Node class | |
class Node: | |
# Constructor to initialize the node object | |
def __init__(self, data): | |
self.data = data | |
self.next = None | |
class LinkedList: | |
# Function to initialize head | |
def __init__(self): | |
self.head = None | |
# Function to insert a new node at the beginning | |
def push(self, new_data): | |
new_node = Node(new_data) | |
new_node.next = self.head | |
self.head = new_node | |
# Given a reference to the head of a list and a key, | |
# delete the first occurence of key in linked list | |
def deleteNode(self, key): | |
# Store head node | |
temp = self.head | |
# If head node itself holds the key to be deleted | |
if (temp is not None): | |
if (temp.data == key): | |
self.head = temp.next | |
temp = None | |
return | |
# Search for the key to be deleted, keep track of the | |
# previous node as we need to change 'prev.next' | |
while(temp is not None): | |
if temp.data == key: | |
break | |
prev = temp | |
temp = temp.next | |
# if key was not present in linked list | |
if(temp == None): | |
return | |
# Unlink the node from linked list | |
prev.next = temp.next | |
temp = None | |
# Utility function to print the linked LinkedList | |
def printList(self): | |
temp = self.head | |
while(temp): | |
print " %d" %(temp.data), | |
temp = temp.next | |
# Driver program | |
llist = LinkedList() | |
llist.push(7) | |
llist.push(1) | |
llist.push(3) | |
llist.push(2) | |
print "Created Linked List: " | |
llist.printList() | |
llist.deleteNode(1) | |
print "\nLinked List after Deletion of 1:" | |
llist.printList() | |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
_ |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment