Problem 1698. Connect Four: find winning move

Created by Matthew Eicholtz

Solve Later

{"relationships":[{"relationshipType":"http://schemas.mathworks.com/matlab/code/2013/relationships/document","targetMode":"","relationshipId":"rId1","target":"/matlab/document.xml"},{"relationshipType":"http://schemas.mathworks.com/matlab/code/2013/relationships/output","targetMode":"","relationshipId":"rId2","target":"/matlab/output.xml"}],"parts":[{"partUri":"/matlab/document.xml","relationship":[],"contentType":"application/vnd.mathworks.matlab.code.document+xml","content":"<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<w:document xmlns:w=\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\"><w:body><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>Inspired by</w:t></w:r><w:r><w:t> </w:t></w:r><w:hyperlink w:docLocation=\"http://www.mathworks.com/matlabcentral/cody/problems/90-connect-four-win-checker\"><w:r><w:t>this problem</w:t></w:r></w:hyperlink><w:r><w:t>...</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:hyperlink w:docLocation=\"http://en.wikipedia.org/wiki/Connect_Four\"><w:r><w:t>Connect Four</w:t></w:r></w:hyperlink><w:r><w:t> is a fun two-player game in which the goal is to be the first player to connect four pieces in a row - horizontally, vertically, or diagonally. Players take turns dropping one of their pieces into any of the available columns.</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:rPr><w:b/></w:rPr><w:t>Problem Statement</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>Given an array (size is arbitrary) in which</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"ListParagraph\"/><w:numPr><w:numId w:val=\"1\"/></w:numPr></w:pPr><w:r><w:t>0 : space is empty</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"ListParagraph\"/><w:numPr><w:numId w:val=\"1\"/></w:numPr></w:pPr><w:r><w:t>1 : player 1 piece</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"ListParagraph\"/><w:numPr><w:numId w:val=\"1\"/></w:numPr></w:pPr><w:r><w:t>2 : player 2 piece</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>return the column that player 1 should play in to win the game. If there is more than one winning move, return a row vector of appropriate columns. If there are currently no winning moves, return [].</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:rPr><w:b/></w:rPr><w:t>Assumptions</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"ListParagraph\"/><w:numPr><w:numId w:val=\"1\"/></w:numPr></w:pPr><w:r><w:t>Pieces fall to the bottommost available row in each column, as in the real game</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"ListParagraph\"/><w:numPr><w:numId w:val=\"1\"/></w:numPr></w:pPr><w:r><w:t>The input grid will always represent a valid game state</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:rPr><w:b/></w:rPr><w:t>Example</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>If</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"code\"/></w:pPr><w:r><w:t><![CDATA[b = [0 0 0 0 0 0 0;\n 0 0 0 0 0 0 0;\n 0 0 0 2 0 0 0;\n 0 0 0 1 0 0 0;\n 0 0 0 2 2 0 0;\n 0 0 2 1 1 1 0];]]></w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>then</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"code\"/></w:pPr><w:r><w:t><![CDATA[y = 7]]></w:t></w:r></w:p></w:body></w:document>"},{"partUri":"/matlab/output.xml","contentType":"text/xml","content":"<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"no\" ?><embeddedOutputs><metaData><evaluationState>manual</evaluationState><layoutState>code</layoutState><outputStatus>ready</outputStatus></metaData><outputArray type=\"array\"/><regionArray type=\"array\"/></embeddedOutputs>"}]}

Inspired by <a href = "http://www.mathworks.com/matlabcentral/cody/problems/90-connect-four-win-checker">this problem</a>...<a href = "http://en.wikipedia.org/wiki/Connect_Four">Connect Four</a> is a fun two-player game in which the goal is to be the first player to connect four pieces in a row - horizontally, vertically, or diagonally. Players take turns dropping one of their pieces into any of the available columns.Problem StatementGiven an array (size is arbitrary) in which<ul><li>0 : space is empty</li><li>1 : player 1 piece</li><li>2 : player 2 piece</li></ul>return the column that player 1 should play in to win the game. If there is more than one winning move, return a row vector of appropriate columns. If there are currently no winning moves, return [].Assumptions<ul><li>Pieces fall to the bottommost available row in each column, as in the real game</li><li>The input grid will always represent a valid game state</li></ul>ExampleIf<pre class="language-matlab">b = [0 0 0 0 0 0 0;
 0 0 0 0 0 0 0;
 0 0 0 2 0 0 0;
 0 0 0 1 0 0 0;
 0 0 0 2 2 0 0;
 0 0 2 1 1 1 0];
</pre>then<pre class="language-matlab">y = 7
</pre>

Inspired by <http://www.mathworks.com/matlabcentral/cody/problems/90-connect-four-win-checker this problem>...

<http://en.wikipedia.org/wiki/Connect_Four Connect Four> is a fun two-player game in which the goal is to be the first player to connect four pieces in a row - horizontally, vertically, or diagonally. Players take turns dropping one of their pieces into any of the available columns.

*Problem Statement*

Given an array (size is arbitrary) in which

* 0 : space is empty
* 1 : player 1 piece
* 2 : player 2 piece

return the column that player 1 should play in to win the game. If there is more than one winning move, return a row vector of appropriate columns. If there are currently no winning moves, return [].

*Assumptions*

* Pieces fall to the bottommost available row in each column, as in the real game
* The input grid will always represent a valid game state

*Example*

b = [0 0 0 0 0 0 0;
       0 0 0 0 0 0 0;
       0 0 0 2 0 0 0;
       0 0 0 1 0 0 0;
       0 0 0 2 2 0 0;
       0 0 2 1 1 1 0];

then

y = 7

Solve

Solution Stats

116 Solutions
21 Solvers

Last Solution submitted on May 21, 2022

Last 200 Solutions

Problem Comments

Solution Comments

Solution 276412

1 Comment

1 Comment

Richard Zapor on 14 Jul 2013

Very creative usage of blkdiag in collaboration with conv2. I prefer nnz over "any" for speed and compactness.

Problem Recent Solvers21

Problem Tags

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!