#Game of nim in java how to

The following pseudocode describes the remaining details of our algorithm.

We will repeat the loop while there are more than 0 sticks remaining. Thus, we can use the game’s state-the number of sticks left-as our loop’s entry condition. The game is over when there are no more sticks to pick up. The user and the computer will repeatedly take turns picking up sticks until the game is over. In fact, the main challenge for this part of our problem is designing the run() method, which will use a loop algorithm to play the game. It will use the OneRowNim object to keep track of the game. OneRowNimApp will use the KeyboardReader object to prompt the user, to display the program’s output, and to perform input from the keyboard. As shown in Figure, the OneRowNimApp class will contain the run() method that controls the game’s progress. Unlike in the greeter example, we will use a third object to serve as the main program. To do so requires no changes to KeyboardReader (Fig. Let’s now focus on connecting a OneRowNim instance with a KeyboardReader instance, the command-line interface we developed at the beginning of this chapter. Figure 4.23 shows the UML diagram of the OneRowNim class as described at the end of the previous chapter. Finally, the game ensures that players cannot cheat, either by taking too few or too many sticks on one turn. Also, an instance of OneRowNim keeps track of whose turn it is and can determine if the game is over and who the winner is when the game is over. Thus, we know that after each legal move, the number of sticks will decline, until it is 0 or less, which indicates that the game is over. Recall that we designed the OneRowNim class to maintain the state of the game and to provide methods that enforce the rules of the game. One goal of our design was to develop the OneRowNim class so that it can be used, without changes, with either a command-line interface or a GUI.

We wish to develop an application program so that the user of the program can play this game against the computer, that is, against the program.Īs in our other examples in this chapter, our design will divide this problem into two primary objects: a computational object, in this case OneRowNim, and a user interface object, for which we will use either a KeyboardReader or a OneRowNimGUI. Players take turns picking up 1, 2 or 3 sticks, and the player to pick up the last stick loses. As you recall, the One Row Nim game starts with, say, 21 sticks on a table.

#Game of nim in java how to

In this section, we show how to develop alternative interfaces for our case study game of One Row Nim that was developed in the two previous chapters.