LinkedList4.cpp

// https://practice.geeksforgeeks.org/problems/delete-without-head-pointer/1
// Delete without head pointer
// { Driver Code Starts
#include <bits/stdc++.h>
using namespace std;

/* Link list node */
struct Node
{
    int data;
    struct Node *next;
    Node(int x)
    {
        data = x;
        next = NULL;
    }
} * head;

Node *findNode(Node *head, int search_for)
{
    Node *current = head;
    while (current != NULL)
    {
        if (current->data == search_for)
            break;
        current = current->next;
    }
    return current;
}

void insert()
{
    int n, i, value;
    Node *temp;
    scanf("%d", &n);

    for (i = 0; i < n; i++)
    {
        scanf("%d", &value);
        if (i == 0)
        {
            head = new Node(value);
            temp = head;
            continue;
        }
        else
        {
            temp->next = new Node(value);
            temp = temp->next;
            temp->next = NULL;
        }
    }
}

/* Function to print linked list */
void printList(Node *node)
{
    while (node != NULL)
    {
        printf("%d ", node->data);
        node = node->next;
    }
    cout << endl;
}

void deleteNode(Node *node_ptr);

int main(void)
{

    int t, k, n, value;

    scanf("%d", &t);
    while (t--)
    {
        insert();
        scanf("%d", &k);
        Node *del = findNode(head, k);
        if (del != NULL && del->next != NULL)
        {
            deleteNode(del);
        }
        printList(head);
    }
    return (0);
}

void deleteNode(Node *node)
{
    // Your code here
    Node *temp = node->next;
    node->data = temp->data;
    node->next = temp->next;
    delete temp;
}