Create assignment_2

[omarahmed2205]

#include
using namespace std;

struct Node {
int data;
Node* next;
Node* prev;
Node(int val) : data(val), next(nullptr), prev(nullptr) {}
};

Node* mergeLists(Node* L1, Node* L2) {
if (!L1) return L2;
if (!L2) return L1;

if (L1->data < L2->data) {
    L1->next = mergeLists(L1->next, L2);
    return L1;
} else {
    L2->next = mergeLists(L1, L2->next);
    return L2;
}

}

void swapAdjacentSingly(Node*& head, int key) {
if (!head || !head->next) return;
Node* prev = nullptr, curr = head;
while (curr && curr->next) {
if (curr->data == key) {
Node temp = curr->next;
curr->next = temp->next;
temp->next = curr;
if (prev) prev->next = temp;
else head = temp;
break;
}
prev = curr;
curr = curr->next;
}
}

void swapAdjacentDoubly(Node*& head, int key) {
if (!head || !head->next) return;
Node* curr = head;
while (curr && curr->next) {
if (curr->data == key) {
Node* temp = curr->next;
if (temp->next) temp->next->prev = curr;
if (curr->prev) curr->prev->next = temp;
else head = temp;

        curr->next = temp->next;
        temp->prev = curr->prev;
        temp->next = curr;
        curr->prev = temp;
        break;
    }
    curr = curr->next;
}

}

void printList(Node* head) {
while (head) {
cout << head->data << " ";
head = head->next;
}
cout << endl;
}

int main() {
Node* L1 = new Node(1);
L1->next = new Node(3);
L1->next->next = new Node(5);

Node* L2 = new Node(2);
L2->next = new Node(4);
L2->next->next = new Node(6);

Node* merged = mergeLists(L1, L2);
printList(merged);

Node* singly = new Node(10);
singly->next = new Node(20);
singly->next->next = new Node(30);
swapAdjacentSingly(singly, 20);
printList(singly);

Node* doubly = new Node(10);
doubly->next = new Node(20);
doubly->next->prev = doubly;
doubly->next->next = new Node(30);
doubly->next->next->prev = doubly->next;
swapAdjacentDoubly(doubly, 20);
printList(doubly);

return 0;

}