Day 129: Union of Two Linked Lists.cpp

 public:
    struct Node* makeUnion(struct Node* head1, struct Node* head2)
    {
        set<int> set;
    
    while (head1 != nullptr) {
        set.insert(head1->data);
        head1 = head1->next;
    }
    
    while (head2 != nullptr) {
        set.insert(head2->data);
        head2 = head2->next;
    }
    
    Node* curr = nullptr;
    Node* start = nullptr;
    
    for (int x : set) {
        if (start == nullptr) {
            start = new Node(x);
            curr = start;
        } else {
            curr->next = new Node(x);
            curr = curr->next;
        }
    }
    
    return start;
    }