Code
#include <bits/stdc++.h>
using namespace std;

// Definition of a node in the linked list
struct ListNode {
    int val;
    ListNode* next;
    ListNode(int x) : val(x), next(NULL) {}
};

// Function to delete the head node
ListNode* deleteHead(ListNode* head) {
    // If list is empty, return null
    if (head == NULL) return NULL;
    
    // Store next node after head
    ListNode* newHead = head->next;
    
    // Free memory of old head
    delete head;
    
    // Return new head of the list
    return newHead;
}

// Driver function
int main() {
    // Create a simple linked list: 1 -> 2 -> 3
    ListNode* head = new ListNode(1);
    head->next = new ListNode(2);
    head->next->next = new ListNode(3);

    cout << "Before deletion: ";
    for (ListNode* temp = head; temp != NULL; temp = temp->next)
        cout << temp->val << " ";
    cout << endl;

    // Delete the head node
    head = deleteHead(head);

    cout << "After deletion: ";
    for (ListNode* temp = head; temp != NULL; temp = temp->next)
        cout << temp->val << " ";
    cout << endl;

    return 0;
}
// Definition of a node in the linked list
class ListNode {
    int val;
    ListNode next;
    ListNode(int x) { val = x; next = null; }
}

class Solution {
    // Functi