1.3-Object-Georienteerd-Programmeren
Bingo mill
With this assignment we are going to build a bingo mill. Next week you will build the rest of the game. Read the assignment carefully before you start programming!
A bingo mill is a device that is used to determine the next number for the game of bingo. The balls in the mill run from 1 to 75.
When playing the game, each number can only be drawn once! You will also need to build a reset() function so that the game can be played again.
Requirements:
- Make sure you have a constructor with which the bingo mill can be built and all balls (numbers 1 to 75 in a list) can be added.
- Once the numbers have been created, the list must be shuffled (see shuffle).
- A
getNumberOfBallsRemaining()method indicating how many balls are left in the device. - A
draw()method that returns the next ball. When someone calls thedraw()method and there are no more balls left in the device, this method returns the value -1. - A
reset()method that resets the device.
Shuffle:
To make sure that we constantly get a new random ball out of the bingo mill we are going to build our own shuffle algorithm.
As soon as the bingo mill is created, or when someone invokes the reset() method, the numbers 1 to 75 will be added to the machine.
Then we can shuffle the list with the following algorithm steps:
- Generate 2 random indexes and swap the elements in these two places.
- Repeat this a few hundred times.
By first filling in the list with all unique values (1-75) and then shuffling it, we can be sure that all numbers appear and there are no duplicates. Now you still have to figure out how to return the numbers 1-for-1!
Example
