How do I merge two linked lists in C++?

How do I merge two linked lists in C++?

To merge two linked lists in C++, you can create a new list and iterate through both lists, adding the smaller node to the new list.

Can you show me a code example for that?

Sure! Here's a simple example:

struct Node {
    int data;
    Node* next;
};

Node* mergeLists(Node* l1, Node* l2) {
    Node dummy;
    Node* tail = &dummy;
    dummy.next = nullptr;

    while (l1 != nullptr && l2 != nullptr) {
        if (l1->data < l2->data) {
            tail->next = l1;
            l1 = l1->next;
        } else {
            tail->next = l2;
            l2 = l2->next;
        }
        tail = tail->next;
    }
    tail->next = (l1 != nullptr) ? l1 : l2;
    return dummy.next;
}

This function merges two sorted linked lists.

What if the linked lists are not sorted?

If the linked lists are not sorted, you would need to sort them first before merging. You can use a sorting algorithm like merge sort.

Can you explain how to sort a linked list in C++?

Certainly! You can implement merge sort for linked lists. It involves splitting the list into halves, sorting each half, and then merging them back together.