delete_circular_linkedlist_hacktoberfest.cpp

#include <bits/stdc++.h>
using namespace std;
class Node {
public:
int data;
Node* next;
};

void push(Node** head_ref, int data)
{
Node* ptr1 = new Node();
ptr1->data = data;
ptr1->next = *head_ref;

if (*head_ref != NULL)
{
Node* temp = *head_ref;
while (temp->next != *head_ref)
temp = temp->next;
temp->next = ptr1;
}

else
ptr1->next = ptr1;

*head_ref = ptr1;
}

void printList(Node* head)
{
Node* temp = head;
if (head != NULL) {
do {
cout << temp->data << " ";
temp = temp->next;
} while (temp != head);
}

cout << endl;
}

void deleteNode(Node** head, int key)
{

if (*head == NULL)
return;

if((*head)->data==key && (*head)->next==*head)
{
free(*head);
*head=NULL;
return;
}

Node *last=*head,*d;
if((*head)->data==key)
{
while(last->next!=*head)
last=last->next;

last->next=(*head)->next;
free(*head);
*head=last->next;
}

while(last->next!=*head&&last->next->data!=key)
{
last=last->next;
}

if(last->next->data==key)
{
d=last->next;
last->next=d->next;
free(d);
}
else
cout<<"no such keyfound";
}

int main()

{
Node* head = NULL;
push(&head, 2);
push(&head, 5);
push(&head, 7);
push(&head, 8);
push(&head, 10);

cout << "List Before Deletion: ";
printList(head);

deleteNode(&head, 7);

cout << "List After Deletion: ";
printList(head);

return 0;
}