On this page and the next, students must alternate between two different points of view: (1) thinking about tic-tac-toe as a game, articulating the rules they use themselves when playing (2) thinking about the problem of embodying those rules in a computer program.On this page, students explore their tic-tac-toe strategy using the program they have built, but this could also be done on paper.Make the shift from the student's intuitive, informal tic-tac-toe strategy to an explicit, formal, algorithmic set of rules.Don't let them be too caught up in coding details to appreciate what they've done! They have now written a program that has goal-directed behavior, trying to win at Tic-Tac-Toe. This page is a turning point for students.Use the broadcast command, when I receive event, and message reporter to implement a computer player.One could say that board is for the conversation between the user and the program, while status of all winning triples is for the program thinking about its strategy. Status of all winning triples represents the same board status, so in a sense it's redundant, but it presents that information in a form that's structured for the decision of the computer's move. Board is the user interface's representation of who has moved where on the board, a straightforward list of nine squares, each of which can be X, O, or the square number to indicate empty. The last problem is at the heart of the actual program consider having a whole-class discussion about it.It's not any arbitrary set of three squares it's a set of three squares that count as a win: a row, a column, or a diagonal. Students must understand the idea of a triple in this program.

You may find it helpful to have students write out their description of these six blocks and how they work.

Next year: need to rename 'The procedure TicTacToe wins' -MF, 6/18/18

Kontakt 6 player 15 minutes