Recursion - Unit 10

Important Notes:

What Is a Java Method?

• A method in Java is a reusable block of code that performs a specific task.
• Consists of an access modifier (e.g., public or private), a return type (e.g., void if it doesn’t return a value), a method name, optional parameters enclosed in parentheses, and a method body enclosed in curly braces.

Part (a):

• this question usually requires you to write a certain method that fits the given test cases and "rules" provided by the problem
• rules + test cases may be provided as a table or as example method calls
• a precondition/postcondition may be provided by the problem.
• a boilerplate segment containing a method declaration is also given

Point Deductions:

Part (b):

• this part is similar to part (a) and typically asks you to write a method that satisfies the given set of rules.
• it may build upon the method created in part (a) (when this is done, it allows you to assume that the method in part (a) works as intended)

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) {
        double conditions = (Math.random() * 100);
        int totalFoodEaten = 0;

        if(conditions >= 5.0)
        {
            for (int birds = 1; birds <= numBirds; birds++) {
                int foodEaten = (int) (Math.random() * (50 - 10 + 1)) + 10;
                totalFoodEaten += foodEaten;
            }
            if (totalFoodEaten >= currentFood)
            {
                System.out.println("All food in feeder eaten!");
                currentFood = 0;
            }
            else
            {
                currentFood = currentFood - totalFoodEaten;
                System.out.println(currentFood + " grams left in feeder");
            }
        }
        else
        {
            currentFood = 0;
            System.out.println("Bear ate all the food. " + currentFood + " grams left in feeder.");
        }
    }

    /**
     * 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;
        for (int days = 1; days <= numDays; days++)
        {
            if (currentFood > 0)
            {
                System.out.println("Day: "+ days);
                simulateOneDay(numBirds);
                daysWithFood++;
            }
            else
            {
                break;
            }
        }
        return daysWithFood;

    }
}

Feeder feeder = new Feeder(2400);
// feeder.simulateOneDay(12); // Runs one day simulation with 12 as number of birds in simulation.
feeder.simulateManyDays(10, 5); // Runs multiple days with 10 being number of birds and 5 being days in simulation.

Day: 1
2125 grams left in feeder
Day: 2
Bear ate all the food. 0 grams left in feeder.





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