Activities

S9Problem1.java

import java.util.*;    

public class S9Problem1 {
    public static void main(String[] args) {
        System.out.println("Problem 1");
        Scanner in = new Scanner(System.in);
        


    } 
}

S9Problem2.java

import java.util.*;    

public class S9Problem2 {
    public static void main(String[] args) {
        System.out.println("Problem 2");
        Scanner in = new Scanner(System.in);
        
        
    } 
}

S9Problem3.java

import java.util.*;    

public class S9Problem3 {
    public static void main(String[] args) {
        System.out.println("Problem 3");
        Scanner in = new Scanner(System.in);
  
                            
    } 
} 

S9Problem4.java

import java.util.*;    

public class S9Problem4 {
    public static void main(String[] args) {
        System.out.println("Problem 4");
        Scanner in = new Scanner(System.in);
        
        
    } 
}

S9Problem5.java

import java.util.*;    

public class S9Problem5 {
    public static void main(String[] args) {
        System.out.println("Problem 5");
        Scanner in = new Scanner(System.in);
        
        
    } 
}

S9Problem6.java

import java.util.*;    

public class S9Problem6 {
    public static void main(String[] args) {
        System.out.println("Problem 6");
        Scanner in = new Scanner(System.in);
        
        
    } 
}

S9Problem7.java

import java.util.*;    

public class S9Problem7 {
    public static void main(String[] args) {
        System.out.println("Problem 7");
        Scanner in = new Scanner(System.in);
        
        
    } 
}

S9Problem8.java

import java.util.*;    

public class S9Problem8 {
    public static void main(String[] args) {
        System.out.println("Problem 8");
        Scanner in = new Scanner(System.in);
        
        
    } 
}

S9Problem9.java

import java.util.*;    

public class S9Problem9 {
    public static void main(String[] args) {
        System.out.println("Problem 9");
        Scanner in = new Scanner(System.in);
        
        
    } 
}

S9Problem10.java

import java.util.*;

public class S9Problem10
{
    public static void main(String[] args)
    {
        System.out.println("Problem 10");
        
        // Rewrite this code to use an ArrayList instead of an array
        String[] toDoList = new String[3];
        toDoList[0] = "Do homework";
        toDoList[1] = "Help make dinner";
        toDoList[2] = "Call grandma";

        // changing element 1
        toDoList[1] = "Order pizza";

        System.out.println(toDoList.length + " things to do!");
        System.out.println("Here's the first thing to do: " + toDoList[0]);

        // remove item 0 and move everything down
        //  (this can be done in one method call with ArrayList)
        toDoList[0] = toDoList[1];
        toDoList[1] = toDoList[2];
        toDoList[2] = "";

        System.out.println("Here's the next thing to do: " + toDoList[0]);
        
        
    }
}

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(1.50);
        
        itemNames.add("Milk");
        prices.add(3.25);
        
        itemNames.add("Bananas");
        prices.add(1.25);
    }
    
    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;
        }
        
        // TODO: Loop through both ArrayLists and display:
        // Item number, name, and price
        // Format: "1. Apples - $2.99"
        
    }
    
    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
        
    }
}