Assignment-3

#include <iostream>
using namespace std;

class Node {
public:
    string song;
    Node *next;

    Node() {
        song = "";
        next = NULL;
    }

    Node(string s) {
        song = s;
        next = NULL;
    }
};

class PlayList {
    Node *head;

public:
    PlayList() : head(NULL) {} // Initialize head to NULL

    void AddSong(string s) {
        Node *nn = new Node(s);
        if (head == NULL) {
            head = nn; // Set head to the new node if list is empty
        } else {
            nn->next = head; // Insert new node at the beginning
            head = nn; // Update head to new node
        }
    }

    void DeleteSong(int pos) {
        if (head == NULL) { // List is empty
            cout << "List is empty. No song to delete." << endl;
            return;
        }

        Node* temp = head;

        if (pos == 1) { // Deleting the head node
            head = temp->next; // Move head to the next node
            delete temp; // Free memory
            cout << "Deleted song at position " << pos << endl;
            return;
        }

        // Traverse to the node just before the desired position
        int currpos = 1;
        while (temp != NULL && currpos < pos - 1) {
            temp = temp->next;
            currpos++;
        }

        // If the position is beyond the length of the list
        if (temp == NULL || temp->next == NULL) {
            cout << "Position does not exist." << endl;
            return;
        }

        // Node to be deleted
        Node* toDelete = temp->next;
        temp->next = toDelete->next; // Unlink the node from the list
        delete toDelete; // Free memory
        cout << "Deleted song at position " << pos << endl;
    }

    void DisplayPlayList() {
        Node *temp = head;
        if (temp == NULL) {
            cout << "Playlist is empty." << endl;
            return;
        }
        while (temp != NULL) {
            cout << temp->song << " -> ";
            temp = temp->next;
        }
        cout << "NULL" << endl;
    }

    void DisplaySpecificSongs(int pos) {
        Node *temp = head;
        int currpos = 1;
        while (temp != NULL && currpos < pos) {
            temp = temp->next;
            currpos++;
        }

        // Check if the position is valid
        if (temp == NULL) {
            cout << "Position does not exist." << endl;
        } else {
            cout << "Song at position " << pos << ": " << temp->song << endl;
        }
    }
};

int main() {
    PlayList pl;
    int ch;
    char agree = 'Y';
    do {
        cout << "---MENU---";
        cout << "\n1. Add songs";
        cout << "\n2. Delete Songs";
        cout << "\n3. Display the entire playlist";
        cout << "\n4. Play specific songs";
        cout << "\nChoose from the above: ";
        cin >> ch;
        cin.ignore(); // Clear the newline character from input buffer

        switch (ch) {
            case 1: {
                string song_name;
                cout << "\nEnter the song name: ";
                getline(cin, song_name); // Use getline to allow multi-word names
                pl.AddSong(song_name);
                break;
            }
            case 2: {
                int pos;
                cout << "\nEnter the position where you want to delete: ";
                cin >> pos;
                pl.DeleteSong(pos);
                break;
            }
            case 3:
                pl.DisplayPlayList();
                break;
            case 4: {
                int pos;
                cout << "\nWhich song do you want to play? ";
                cin >> pos;
                pl.DisplaySpecificSongs(pos);
                break;
            }
            default: 
                cout << "\nInvalid choice!" << endl;
        }
        cout << "\nDo you want to continue? (Y/N): ";
        cin >> agree;
    } while (agree == 'y' || agree == 'Y');

    return 0;
}