Activities

S10Problem1.java

import java.util.*;    

public class S10Problem1 {
    public static void main(String[] args) {
        System.out.println("Problem 1");
        Scanner in = new Scanner(System.in);
        


    } 
}

S10Problem2.java

import java.util.*;    

public class S10Problem2 {
    public static void main(String[] args) {
        System.out.println("Problem 2");
        Scanner in = new Scanner(System.in);
        


    } 
}

GroceryStoreManager.java

import java.util.*;

public class GroceryStoreManager {
    // Parallel ArrayLists
    private static ArrayList<String> itemNames = new ArrayList<>();
    private static ArrayList<Double> prices = new ArrayList<>();

    private static Scanner scanner = new Scanner(System.in);

    public static void main(String[] args) {
        // Add some sample data
        addSampleData();

        int choice;
        do {
            displayMenu();
            choice = scanner.nextInt();
            scanner.nextLine(); // consume newline

            switch (choice) {
                case 1:
                    addNewItem();
                    break;
                case 2:
                    removeItem();
                    break;
                case 3:
                    updatePrice();
                    break;
                case 4:
                    displayAllItems();
                    break;
                case 5:
                    findMostExpensive();
                    break;
                case 6:
                    findLeastExpensive();
                    break;
                case 7:
                    System.out.println("Goodbye!");
                    break;
                default:
                    System.out.println("Invalid choice. Please try again.");
            }
        } while (choice != 7);
    }

    public static void displayMenu() {
        System.out.println("\n=== Grocery Store Inventory ===");
        System.out.println("1. Add new item");
        System.out.println("2. Remove item");
        System.out.println("3. Update price");
        System.out.println("4. Display all items");
        System.out.println("5. Find most expensive item");
        System.out.println("6. Find least expensive item");
        System.out.println("7. Exit");
        System.out.print("Enter your choice: ");
    }

    public static void addSampleData() {
        itemNames.add("Apples");
        prices.add(2.99);

        itemNames.add("Bread");
        prices.add(2.50);

        itemNames.add("Milk");
        prices.add(4.99);

        itemNames.add("Bananas");
        prices.add(2.99);
    }

    public static void addNewItem() {
        System.out.print("Enter item name: ");
        String name = scanner.nextLine();

        System.out.print("Enter price: $");
        double price = scanner.nextDouble();

        // TODO: Add the item name and price to their respective ArrayLists

        System.out.println("Item added successfully!");
    }

    public static void removeItem() {
        displayAllItems();

        if (itemNames.size() == 0) {
            System.out.println("No items to remove!");
            return;
        }

        System.out.print("Enter the number of the item to remove: ");
        int index = scanner.nextInt() - 1;

        // TODO: Check if index is valid (between 0 and size-1)
        // TODO: Remove item from both ArrayLists at the same index

        System.out.println("Item removed successfully!");
    }

    public static void updatePrice() {
        displayAllItems();

        if (itemNames.size() == 0) {
            System.out.println("No items to update!");
            return;
        }

        System.out.print("Enter the number of the item to update: ");
        int index = scanner.nextInt() - 1;

        // TODO: Check if index is valid
        // TODO: Ask for new price and update the prices ArrayList using .set()

        System.out.println("Price updated successfully!");
    }

    public static void displayAllItems() {
        System.out.println("\n=== Current Inventory ===");

        if (itemNames.size() == 0) {
            System.out.println("No items in inventory!");
            return;
        }

        System.out.println("Item\tPrice");
        for (int i = 0; i < itemNames.size(); i++) {
            System.out.println(itemNames.get(i) + "\t$" + prices.get(i));
        }

    }

    public static void findMostExpensive() {
        if (prices.size() == 0) {
            System.out.println("No items in inventory!");
            return;
        }

        // TODO: Find the index of the item with the highest price
        // Display the item name and price
        // Hint: Use a loop to compare prices and track the highest

    }

    public static void findLeastExpensive() {
        if (prices.size() == 0) {
            System.out.println("No items in inventory!");
            return;
        }

        // TODO: Find the index of the item with the lowest price
        // Display the item name and price
        // Hint: Use a loop to compare prices and track the lowest

    }
}

GroceryStoreManagerV2.java

import java.util.*;

public class GroceryStoreManagerV2 {
    // HashMap instead of parallel ArrayLists
    private static HashMap<String, Double> inventory = new HashMap<>();
    private static Scanner scanner = new Scanner(System.in);

    public static void main(String[] args) {
        // Add some sample data
        addSampleData();

        int choice;
        do {
            displayMenu();
            choice = scanner.nextInt();
            scanner.nextLine(); // consume newline

            switch (choice) {
                case 1:
                    addNewItem();
                    break;
                case 2:
                    removeItem();
                    break;
                case 3:
                    updatePrice();
                    break;
                case 4:
                    displayAllItems();
                    break;
                case 5:
                    findMostExpensive();
                    break;
                case 6:
                    findLeastExpensive();
                    break;
                case 7:
                    System.out.println("Goodbye!");
                    break;
                default:
                    System.out.println("Invalid choice. Please try again.");
            }
        } while (choice != 7);
    }

    public static void displayMenu() {
        System.out.println("\n=== Grocery Store Inventory ===");
        System.out.println("1. Add new item");
        System.out.println("2. Remove item");
        System.out.println("3. Update price");
        System.out.println("4. Display all items");
        System.out.println("5. Find most expensive item");
        System.out.println("6. Find least expensive item");
        System.out.println("7. Exit");
        System.out.print("Enter your choice: ");
    }

    public static void addSampleData() {
        inventory.put("Apples", 2.99);
        inventory.put("Bread", 2.50);
        inventory.put("Milk", 4.99);
        inventory.put("Bananas", 2.99);
    }

    public static void addNewItem() {
        System.out.print("Enter item name: ");
        String name = scanner.nextLine();

        System.out.print("Enter price: $");
        double price = scanner.nextDouble();

        // TODO: Add the item name and price to the HashMap
        // Example: inventory.put(name, price);

        System.out.println("Item added successfully!");
    }

    public static void removeItem() {
        displayAllItems();

        if (inventory.isEmpty()) {
            System.out.println("No items to remove!");
            return;
        }

        System.out.print("Enter the item name to remove: ");
        String name = scanner.nextLine();

        // TODO: Check if the item exists and remove it using inventory.remove(name)

        System.out.println("Item removed successfully!");
    }

    public static void updatePrice() {
        displayAllItems();

        if (inventory.isEmpty()) {
            System.out.println("No items to update!");
            return;
        }

        System.out.print("Enter the item name to update: ");
        String name = scanner.nextLine();

        // TODO: Check if item exists
        // TODO: Ask for new price and update using inventory.put(name, newPrice)

        System.out.println("Price updated successfully!");
    }

    public static void displayAllItems() {
        System.out.println("\n=== Current Inventory ===");

        if (inventory.isEmpty()) {
            System.out.println("No items in inventory!");
            return;
        }

        System.out.println("Item\tPrice");
        for (String name : inventory.keySet()) {
            System.out.println(name + "\t$" + inventory.get(name));
        }
    }

    public static void findMostExpensive() {
        if (inventory.isEmpty()) {
            System.out.println("No items in inventory!");
            return;
        }

        // TODO: Find the item with the highest price
        // Hint: Use a loop through inventory.entrySet() to compare values
        // Example: if (entry.getValue() > max), then track max and key

        // TODO: Display the item name and price
    }

    public static void findLeastExpensive() {
        if (inventory.isEmpty()) {
            System.out.println("No items in inventory!");
            return;
        }

        // TODO: Find the item with the lowest price
        // Hint: Use a loop through inventory.entrySet() to compare values

        // TODO: Display the item name and price
        
    }
}

PlaylistManager.java

import java.io.*;
import java.util.*;

public class PlaylistManager {
    private static HashMap<String, String> playlist = new HashMap<>();
    private static Scanner scanner = new Scanner(System.in);

    public static void main(String[] args) {
        loadFromCSV("playlist.csv");

        int choice;
        do {
            displayMenu();
            choice = scanner.nextInt();
            scanner.nextLine(); // consume newline

            switch (choice) {
                case 1:
                    addSong();
                    break;
                case 2:
                    removeSong();
                    break;
                case 3:
                    randomSong();
                    break;
                case 4:
                    displayAllSongs();
                    break;
                case 5:
                    System.out.println("Goodbye!");
                    break;
                default:
                    System.out.println("Invalid choice.");
            }
        } while (choice != 5);
    }

    public static void loadFromCSV(String filename) {
        try {
            File file = new File(filename);
            Scanner fileScanner = new Scanner(file);

            // Skip header
            if (fileScanner.hasNextLine()) {
                fileScanner.nextLine();
            }

            while (fileScanner.hasNextLine()) {
                String line = fileScanner.nextLine();
                String[] parts = line.split(",");

                if (parts.length == 2) {
                    String artist = parts[0].trim();
                    String title = parts[1].trim();
                    playlist.put(title, artist);
                }
            }

            fileScanner.close();
            System.out.println("Playlist loaded.");
        } catch (FileNotFoundException e) {
            System.out.println("CSV file not found.");
        }
    }

    public static void displayMenu() {
        System.out.println("\n🎶 Playlist Manager 🎶");
        System.out.println("1. Add a new song");
        System.out.println("2. Remove a song");
        System.out.println("3. Search for a song");
        System.out.println("4. Display entire playlist");
        System.out.println("5. Exit");
        System.out.print("Choose an option: ");
    }

    public static void addSong() {
        System.out.print("Enter song title: ");
        String title = scanner.nextLine();

        System.out.print("Enter artist name: ");
        String artist = scanner.nextLine();

        // TODO
    }

    public static void removeSong() {
        System.out.print("Enter song title to remove: ");
        String title = scanner.nextLine();
        // TODO

    }

    public static void randomSong() {
        System.out.print("Here's a random song!");
        // TODO
        
    }

    public static void displayAllSongs() {
        if (playlist.isEmpty()) {
            System.out.println("Your playlist is empty.");
            return;
        }

        System.out.println("\n🎧 Your Playlist:");
        for (String title : playlist.keySet()) {
            System.out.println(title + " - " + playlist.get(title));
        }
    }
}