Problem 2565. Determine the Result of a Move in Reversi

Created by Ned Gulley

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Note: This is closely related to <a href = "http://www.mathworks.com/matlabcentral/cody/problems/2538-find-the-next-legal-move-in-reversi">Problem 2538</a>, Find the Next Legal Move in Reversi.<a href = "http://en.wikipedia.org/wiki/Reversi">Reversi</a>, also known as Othello, is a game in which reversible white/black chips are placed on a grid. The goal is to have the most pieces once the board is full (i.e. there are no more legal moves). A move, to be legal, must flip at least one opponent's chip by flanking it. "Flanking" occurs by surrounding a line of opposing chips with two of your own. It can occur on straight lines and diagonals.We represent a small 4x4 board this way, with 0 for empty squares, 1 for black chips, and 2 for white chips,<pre> [ 0 0 0 0
 0 1 2 0
 0 2 1 0 
 0 0 0 0 ]</pre>Now assume black now moves where the asterisk (*) is placed. This is column-wise matrix index position 14.<pre> [ 0 0 0 0
 0 1 2 *
 0 2 1 0 
 0 0 0 0 ]</pre>Your Cody challenge is to determine the state of the board once the appropriate chips have been flipped over. In this case the correct answer would be<pre> [ 0 0 0 0
 0 1 1 1
 0 2 1 0 
 0 0 0 0 ]</pre>ExampleFor the inputs boardIn, side, and move<pre> boardIn = ...
 [ 0 0 0 0 0
 0 1 1 2 2 
 0 2 1 1 0
 0 0 2 1 0 
 0 0 0 0 0 ]
 side = 1 (black)
 move = 9 (matrix index of black's next move)</pre>The correct answer is<pre> boardOut = ...
 [ 0 0 0 0 0
 0 1 1 2 2 
 0 1 1 1 0
 0 1 1 1 0 
 0 0 0 0 0 ]</pre>

Note: This is closely related to <http://www.mathworks.com/matlabcentral/cody/problems/2538-find-the-next-legal-move-in-reversi Problem 2538>, Find the Next Legal Move in Reversi.

<http://en.wikipedia.org/wiki/Reversi Reversi>, also known as Othello, is a game in which reversible white/black chips are placed on a grid. The goal is to have the most pieces once the board is full (i.e. there are no more legal moves). A move, to be legal, must flip at least one opponent's chip by flanking it. "Flanking" occurs by surrounding a line of opposing chips with two of your own. It can occur on straight lines and diagonals.

We represent a small 4x4 board this way, with 0 for empty squares, 1 for black chips, and 2 for white chips,

[ 0 0 0 0
   0 1 2 0
   0 2 1 0 
   0 0 0 0 ]

Now assume black now moves where the asterisk (*) is placed. This is column-wise matrix index position 14.

[ 0 0 0 0
   0 1 2 *
   0 2 1 0 
   0 0 0 0 ]

Your Cody challenge is to determine the state of the board once the appropriate chips have been flipped over. In this case the correct answer would be

[ 0 0 0 0
   0 1 1 1
   0 2 1 0 
   0 0 0 0 ]

Example

For the inputs boardIn, side, and move

boardIn = ...
   [ 0 0 0 0 0
     0 1 1 2 2 
     0 2 1 1 0
     0 0 2 1 0 
     0 0 0 0 0 ]
 side = 1 (black)
 move = 9 (matrix index of black's next move)

The correct answer is

boardOut = ...
   [ 0 0 0 0 0
     0 1 1 2 2 
     0 1 1 1 0
     0 1 1 1 0 
     0 0 0 0 0 ]

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Last Solution submitted on Aug 14, 2021

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Solution 498034

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Ned Gulley on 20 Jan 2015

This code is referenced in the following blog post: http://blogs.mathworks.com/community/2015/01/19/robot-game-playing-in-matlab-part-2/

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Problem 2565. Determine the Result of a Move in Reversi

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