{"group":{"id":1,"name":"Community","lockable":false,"created_at":"2012-01-18T18:02:15.000Z","updated_at":"2025-12-14T01:33:56.000Z","description":"Problems submitted by members of the MATLAB Central community.","is_default":true,"created_by":161519,"badge_id":null,"featured":false,"trending":false,"solution_count_in_trending_period":0,"trending_last_calculated":"2025-12-14T00:00:00.000Z","image_id":null,"published":true,"community_created":false,"status_id":2,"is_default_group_for_player":false,"deleted_by":null,"deleted_at":null,"restored_by":null,"restored_at":null,"description_opc":null,"description_html":null,"published_at":null},"problems":[{"id":44850,"title":"X O X O","description":"On a noughts and crosses board, how many possible unique combinations are there given a square grid of length n?\r\n\r\nAssumptions/constraints:\r\n\r\n* All squares are populated.\r\n* \r\n* Number of naughts and number of crosses can only differ by a maximum of 1. I.E. The game was played until the board was full\r\n* \r\n* Minimum Grid size (n) = 1x1\r\n\r\nThis is a discrete maths question, which can be simplified by focussing on one of the options. If we look at the\r\noptions for locating just the crosses on the grid, we know that the remaining locations must contain naughts and so similarly for the opposite condition.\r\nThe maths is relatively simple, and is the solution to \"choose k from n\".\r\n\r\n19-Feb-19 -  Test suite updated to take into account solutions where the opposing player goes first.\r\n\r\n","description_html":"\u003cp\u003eOn a noughts and crosses board, how many possible unique combinations are there given a square grid of length n?\u003c/p\u003e\u003cp\u003eAssumptions/constraints:\u003c/p\u003e\u003cul\u003e\u003cli\u003eAll squares are populated.\u003c/li\u003e\u003cli\u003e\u003c/li\u003e\u003cli\u003eNumber of naughts and number of crosses can only differ by a maximum of 1. I.E. The game was played until the board was full\u003c/li\u003e\u003cli\u003e\u003c/li\u003e\u003cli\u003eMinimum Grid size (n) = 1x1\u003c/li\u003e\u003c/ul\u003e\u003cp\u003eThis is a discrete maths question, which can be simplified by focussing on one of the options. If we look at the\r\noptions for locating just the crosses on the grid, we know that the remaining locations must contain naughts and so similarly for the opposite condition.\r\nThe maths is relatively simple, and is the solution to \"choose k from n\".\u003c/p\u003e\u003cp\u003e19-Feb-19 -  Test suite updated to take into account solutions where the opposing player goes first.\u003c/p\u003e","function_template":"function y = xoxo(n)\r\n  y = n;\r\nend","test_suite":"%%\r\nn = 3;\r\ny_correct = 252;\r\nassert(isequal(xoxo(n),y_correct));\r\n%%\r\n% sneaky... With n=1 this is a single player game though the outcome is 2 as you can still choose 'x' or 'o' to play.\r\nn = 1; \r\ny_correct = 2;\r\nassert(isequal(xoxo(n),y_correct));","published":true,"deleted":false,"likes_count":2,"comments_count":4,"created_by":179218,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":40,"test_suite_updated_at":"2019-04-08T12:17:28.000Z","rescore_all_solutions":false,"group_id":1,"created_at":"2019-02-15T13:48:23.000Z","updated_at":"2026-03-04T22:02:57.000Z","published_at":"2019-02-15T13:54:35.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"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\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\\n\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eOn a noughts and crosses board, how many possible unique combinations are there given a square grid of length n?\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eAssumptions/constraints:\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"ListParagraph\\\"/\u003e\u003cw:numPr\u003e\u003cw:numId w:val=\\\"1\\\"/\u003e\u003c/w:numPr\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eAll squares are populated.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"ListParagraph\\\"/\u003e\u003cw:numPr\u003e\u003cw:numId w:val=\\\"1\\\"/\u003e\u003c/w:numPr\u003e\u003c/w:pPr\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"ListParagraph\\\"/\u003e\u003cw:numPr\u003e\u003cw:numId w:val=\\\"1\\\"/\u003e\u003c/w:numPr\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eNumber of naughts and number of crosses can only differ by a maximum of 1. I.E. The game was played until the board was full\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"ListParagraph\\\"/\u003e\u003cw:numPr\u003e\u003cw:numId w:val=\\\"1\\\"/\u003e\u003c/w:numPr\u003e\u003c/w:pPr\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"ListParagraph\\\"/\u003e\u003cw:numPr\u003e\u003cw:numId w:val=\\\"1\\\"/\u003e\u003c/w:numPr\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eMinimum Grid size (n) = 1x1\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eThis is a discrete maths question, which can be simplified by focussing on one of the options. If we look at the options for locating just the crosses on the grid, we know that the remaining locations must contain naughts and so similarly for the opposite condition. The maths is relatively simple, and is the solution to \\\"choose k from n\\\".\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003e19-Feb-19 - Test suite updated to take into account solutions where the opposing player goes first.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"},{"id":44851,"title":"X O X Oh!","description":"_This follows on from problem 44850 - X O X O_ \r\n\r\n\u003chttps://www.mathworks.com/matlabcentral/cody/problems/44850-x-o-x-o\u003e\r\n\r\nOn a noughts and crosses board, how many possible unique combinations are there given a square grid of length n?\r\n\r\nAssumptions/constraints:\r\n\r\n* All squares are populated.\r\n\r\n* Number of naughts and number of crosses can only differ by a maximum of 1 I.E. The game was played until the board was full.\r\n\r\n* A solution with more than one \"win\" cannot be valid as the game would have finished before the board was full!","description_html":"\u003cp\u003e\u003ci\u003eThis follows on from problem 44850 - X O X O\u003c/i\u003e\u003c/p\u003e\u003cp\u003e\u003ca href = \"https://www.mathworks.com/matlabcentral/cody/problems/44850-x-o-x-o\"\u003ehttps://www.mathworks.com/matlabcentral/cody/problems/44850-x-o-x-o\u003c/a\u003e\u003c/p\u003e\u003cp\u003eOn a noughts and crosses board, how many possible unique combinations are there given a square grid of length n?\u003c/p\u003e\u003cp\u003eAssumptions/constraints:\u003c/p\u003e\u003cul\u003e\u003cli\u003eAll squares are populated.\u003c/li\u003e\u003c/ul\u003e\u003cul\u003e\u003cli\u003eNumber of naughts and number of crosses can only differ by a maximum of 1 I.E. The game was played until the board was full.\u003c/li\u003e\u003c/ul\u003e\u003cul\u003e\u003cli\u003eA solution with more than one \"win\" cannot be valid as the game would have finished before the board was full!\u003c/li\u003e\u003c/ul\u003e","function_template":"function y = xoxo(n)\r\n  y = n;\r\nend","test_suite":"%%\r\nn = 3;\r\ny_correct = 63;\r\nassert(isequal(xoxo(n),y_correct))\r\n","published":true,"deleted":false,"likes_count":0,"comments_count":1,"created_by":158257,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":13,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":1,"created_at":"2019-02-15T16:42:29.000Z","updated_at":"2024-11-05T01:44:13.000Z","published_at":"2019-02-15T16:42:29.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"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\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\\n\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:i/\u003e\u003c/w:rPr\u003e\u003cw:t\u003eThis follows on from problem 44850 - X O X O\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:hyperlink w:docLocation=\\\"https://www.mathworks.com/matlabcentral/cody/problems/44850-x-o-x-o\\\"\u003e\u003cw:r\u003e\u003cw:t\u003e\u0026lt;https://www.mathworks.com/matlabcentral/cody/problems/44850-x-o-x-o\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:hyperlink\u003e\u003cw:r\u003e\u003cw:t\u003e\u0026gt;\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eOn a noughts and crosses board, how many possible unique combinations are there given a square grid of length n?\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eAssumptions/constraints:\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"ListParagraph\\\"/\u003e\u003cw:numPr\u003e\u003cw:numId w:val=\\\"1\\\"/\u003e\u003c/w:numPr\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eAll squares are populated.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"ListParagraph\\\"/\u003e\u003cw:numPr\u003e\u003cw:numId w:val=\\\"1\\\"/\u003e\u003c/w:numPr\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eNumber of naughts and number of crosses can only differ by a maximum of 1 I.E. The game was played until the board was full.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"ListParagraph\\\"/\u003e\u003cw:numPr\u003e\u003cw:numId w:val=\\\"1\\\"/\u003e\u003c/w:numPr\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eA solution with more than one \\\"win\\\" cannot be valid as the game would have finished before the board was full!\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"}],"problem_search":{"errors":[],"problems":[{"id":44850,"title":"X O X O","description":"On a noughts and crosses board, how many possible unique combinations are there given a square grid of length n?\r\n\r\nAssumptions/constraints:\r\n\r\n* All squares are populated.\r\n* \r\n* Number of naughts and number of crosses can only differ by a maximum of 1. I.E. The game was played until the board was full\r\n* \r\n* Minimum Grid size (n) = 1x1\r\n\r\nThis is a discrete maths question, which can be simplified by focussing on one of the options. If we look at the\r\noptions for locating just the crosses on the grid, we know that the remaining locations must contain naughts and so similarly for the opposite condition.\r\nThe maths is relatively simple, and is the solution to \"choose k from n\".\r\n\r\n19-Feb-19 -  Test suite updated to take into account solutions where the opposing player goes first.\r\n\r\n","description_html":"\u003cp\u003eOn a noughts and crosses board, how many possible unique combinations are there given a square grid of length n?\u003c/p\u003e\u003cp\u003eAssumptions/constraints:\u003c/p\u003e\u003cul\u003e\u003cli\u003eAll squares are populated.\u003c/li\u003e\u003cli\u003e\u003c/li\u003e\u003cli\u003eNumber of naughts and number of crosses can only differ by a maximum of 1. I.E. The game was played until the board was full\u003c/li\u003e\u003cli\u003e\u003c/li\u003e\u003cli\u003eMinimum Grid size (n) = 1x1\u003c/li\u003e\u003c/ul\u003e\u003cp\u003eThis is a discrete maths question, which can be simplified by focussing on one of the options. If we look at the\r\noptions for locating just the crosses on the grid, we know that the remaining locations must contain naughts and so similarly for the opposite condition.\r\nThe maths is relatively simple, and is the solution to \"choose k from n\".\u003c/p\u003e\u003cp\u003e19-Feb-19 -  Test suite updated to take into account solutions where the opposing player goes first.\u003c/p\u003e","function_template":"function y = xoxo(n)\r\n  y = n;\r\nend","test_suite":"%%\r\nn = 3;\r\ny_correct = 252;\r\nassert(isequal(xoxo(n),y_correct));\r\n%%\r\n% sneaky... With n=1 this is a single player game though the outcome is 2 as you can still choose 'x' or 'o' to play.\r\nn = 1; \r\ny_correct = 2;\r\nassert(isequal(xoxo(n),y_correct));","published":true,"deleted":false,"likes_count":2,"comments_count":4,"created_by":179218,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":40,"test_suite_updated_at":"2019-04-08T12:17:28.000Z","rescore_all_solutions":false,"group_id":1,"created_at":"2019-02-15T13:48:23.000Z","updated_at":"2026-03-04T22:02:57.000Z","published_at":"2019-02-15T13:54:35.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"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\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\\n\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eOn a noughts and crosses board, how many possible unique combinations are there given a square grid of length n?\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eAssumptions/constraints:\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"ListParagraph\\\"/\u003e\u003cw:numPr\u003e\u003cw:numId w:val=\\\"1\\\"/\u003e\u003c/w:numPr\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eAll squares are populated.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"ListParagraph\\\"/\u003e\u003cw:numPr\u003e\u003cw:numId w:val=\\\"1\\\"/\u003e\u003c/w:numPr\u003e\u003c/w:pPr\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"ListParagraph\\\"/\u003e\u003cw:numPr\u003e\u003cw:numId w:val=\\\"1\\\"/\u003e\u003c/w:numPr\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eNumber of naughts and number of crosses can only differ by a maximum of 1. I.E. The game was played until the board was full\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"ListParagraph\\\"/\u003e\u003cw:numPr\u003e\u003cw:numId w:val=\\\"1\\\"/\u003e\u003c/w:numPr\u003e\u003c/w:pPr\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"ListParagraph\\\"/\u003e\u003cw:numPr\u003e\u003cw:numId w:val=\\\"1\\\"/\u003e\u003c/w:numPr\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eMinimum Grid size (n) = 1x1\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eThis is a discrete maths question, which can be simplified by focussing on one of the options. If we look at the options for locating just the crosses on the grid, we know that the remaining locations must contain naughts and so similarly for the opposite condition. The maths is relatively simple, and is the solution to \\\"choose k from n\\\".\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003e19-Feb-19 - Test suite updated to take into account solutions where the opposing player goes first.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"},{"id":44851,"title":"X O X Oh!","description":"_This follows on from problem 44850 - X O X O_ \r\n\r\n\u003chttps://www.mathworks.com/matlabcentral/cody/problems/44850-x-o-x-o\u003e\r\n\r\nOn a noughts and crosses board, how many possible unique combinations are there given a square grid of length n?\r\n\r\nAssumptions/constraints:\r\n\r\n* All squares are populated.\r\n\r\n* Number of naughts and number of crosses can only differ by a maximum of 1 I.E. The game was played until the board was full.\r\n\r\n* A solution with more than one \"win\" cannot be valid as the game would have finished before the board was full!","description_html":"\u003cp\u003e\u003ci\u003eThis follows on from problem 44850 - X O X O\u003c/i\u003e\u003c/p\u003e\u003cp\u003e\u003ca href = \"https://www.mathworks.com/matlabcentral/cody/problems/44850-x-o-x-o\"\u003ehttps://www.mathworks.com/matlabcentral/cody/problems/44850-x-o-x-o\u003c/a\u003e\u003c/p\u003e\u003cp\u003eOn a noughts and crosses board, how many possible unique combinations are there given a square grid of length n?\u003c/p\u003e\u003cp\u003eAssumptions/constraints:\u003c/p\u003e\u003cul\u003e\u003cli\u003eAll squares are populated.\u003c/li\u003e\u003c/ul\u003e\u003cul\u003e\u003cli\u003eNumber of naughts and number of crosses can only differ by a maximum of 1 I.E. The game was played until the board was full.\u003c/li\u003e\u003c/ul\u003e\u003cul\u003e\u003cli\u003eA solution with more than one \"win\" cannot be valid as the game would have finished before the board was full!\u003c/li\u003e\u003c/ul\u003e","function_template":"function y = xoxo(n)\r\n  y = n;\r\nend","test_suite":"%%\r\nn = 3;\r\ny_correct = 63;\r\nassert(isequal(xoxo(n),y_correct))\r\n","published":true,"deleted":false,"likes_count":0,"comments_count":1,"created_by":158257,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":13,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":1,"created_at":"2019-02-15T16:42:29.000Z","updated_at":"2024-11-05T01:44:13.000Z","published_at":"2019-02-15T16:42:29.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"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\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\\n\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:i/\u003e\u003c/w:rPr\u003e\u003cw:t\u003eThis follows on from problem 44850 - X O X O\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:hyperlink w:docLocation=\\\"https://www.mathworks.com/matlabcentral/cody/problems/44850-x-o-x-o\\\"\u003e\u003cw:r\u003e\u003cw:t\u003e\u0026lt;https://www.mathworks.com/matlabcentral/cody/problems/44850-x-o-x-o\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:hyperlink\u003e\u003cw:r\u003e\u003cw:t\u003e\u0026gt;\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eOn a noughts and crosses board, how many possible unique combinations are there given a square grid of length n?\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eAssumptions/constraints:\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"ListParagraph\\\"/\u003e\u003cw:numPr\u003e\u003cw:numId w:val=\\\"1\\\"/\u003e\u003c/w:numPr\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eAll squares are populated.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"ListParagraph\\\"/\u003e\u003cw:numPr\u003e\u003cw:numId w:val=\\\"1\\\"/\u003e\u003c/w:numPr\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eNumber of naughts and number of crosses can only differ by a maximum of 1 I.E. The game was played until the board was full.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"ListParagraph\\\"/\u003e\u003cw:numPr\u003e\u003cw:numId w:val=\\\"1\\\"/\u003e\u003c/w:numPr\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eA solution with more than one \\\"win\\\" cannot be valid as the game would have finished before the board was full!\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray 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