// A complete working C++ program to
// demonstrate deletion in singly
// linked list with class
#include <bits/stdc++.h>
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 key, deletes
// the first occurrence of key in linked list
void deleteNode(Node** head_ref, int key)
{
// Store head node
Node* temp = *head_ref;
Node* prev = NULL;
// If head node itself holds
// the key to be deleted
if (temp != NULL && temp->data == key)
{
*head_ref = temp->next; // Changed head
delete temp; // free old head
return;
}
// Else Search for the key to be deleted,
// keep track of the previous node as we
// need to change 'prev->next' */
else
{
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 memory
delete temp;
}
}
// 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;
// Add elements in linked list
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;
}
// This code is contributed by ac121102