Feeder Class Simulation

AP CSA FRQ Tester: Feeder Class Simulation (2024)

This notebook allows you to test your implementation of the simulateOneDay and simulateManyDays methods for the Feeder class.

The test harness will:

1. Append your code to a predefined test structure.
2. Run several test cases.
3. Display the results of the test cases.

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Instructions

1. Add the code as per the FRQ instructions in the //YOUR CODE HERE

2. Run both code cells to test your code for errors against provided test cases

// Your Implementation
import java.util.Random;
public class Feeder {
    public int currentFood; // Amount of food in grams in the feeder

    public Feeder(int initialFood) {
        currentFood = initialFood;
    }

    /**
     * Simulates one day with numBirds birds or possibly a bear at the feeder.
     * Precondition: numBirds > 0
     */
    public void simulateOneDay(int numBirds) {
        Random rand = new Random();
        int chance = rand.nextInt(100); 
        if (chance <= 95) {
            int foodPerBird = rand.nextInt(41) ; 
            int totalFoodEaten = foodPerBird * numBirds;
            if (currentFood >= totalFoodEaten) {
                currentFood -= totalFoodEaten; 
            } else {
                currentFood = 0; 
            }
        } else {
            currentFood = 0;
        }
    }

    /**
     * Simulates numDays of activity at the feeder with numBirds birds.
     * Returns the number of days on which food was found in the feeder.
     * Precondition: numBirds > 0, numDays > 0
     */
    public int simulateManyDays(int numBirds, int numDays) {
        int daysWithFood = 0;
        int day = 0;
        while (day < numDays) {
            if (currentFood > 0) {daysWithFood++; }
            simulateOneDay(numBirds);
            // System.out.println(currentFood);
            day++;
        }
        return daysWithFood;
    }
}

public class FeederTest {
    public static void main(String[] args) {
        StringBuilder results = new StringBuilder();

        // Test Case 1
        Feeder feeder1 = new Feeder(2400);
        feeder1.simulateOneDay(10);
        results.append("Test Case 1: Current food after one day: ").append(feeder1.currentFood).append("\n");

        // Test Case 2
        Feeder feeder2 = new Feeder(250);
        int daysWithFood2 = feeder2.simulateManyDays(3, 5);
        results.append("Test Case 2: Days with food: ").append(daysWithFood2)
               .append(", Remaining food: ").append(feeder2.currentFood).append("\n");

        // Test Case 3
        Feeder feeder3 = new Feeder(0);
        int daysWithFood3 = feeder3.simulateManyDays(5, 10);
        results.append("Test Case 3: Days with food: ").append(daysWithFood3)
               .append(", Remaining food: ").append(feeder3.currentFood).append("\n");

        // Print Results
        System.out.println(results.toString());
    }
}

// Run the Test Harness
FeederTest.main(null);

Test Case 1: Current food after one day: 2120
Test Case 2: Days with food: 5, Remaining food: 0
Test Case 3: Days with food: 0, Remaining food: 0