{"group":{"id":1,"name":"Community","lockable":false,"created_at":"2012-01-18T18:02:15.000Z","updated_at":"2026-05-26T00:16:20.000Z","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":"2026-05-26T00:00:00.000Z","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":43119,"title":"3D indexes","description":"Generalisation in 3 dimensions of the\r\n\u003chttp://nl.mathworks.com/matlabcentral/cody/problems/43117-2d-indexes Problem 43117. 2D Indexes\u003e\r\n\r\nGiven in input the maximum degree P, the algorithm furnishes a ordered list of 3 dimensional vectors [i,j,k] i,j,k\u003e=0 such that i+j+k\u003c=P-1\r\n\r\n  P=2\r\nindexes=[0,0,0;1,0,0;0,1,0;0,0,1]\r\nP=3\r\nindexes=[0,0,0;1,0,0;0,1,0;0,0,1;2,0,0;1,1,0; 1,0,1; 0,2,0; 0,1,1;0,0,2]\r\n","description_html":"\u003cp\u003eGeneralisation in 3 dimensions of the \u003ca href = \"http://nl.mathworks.com/matlabcentral/cody/problems/43117-2d-indexes\"\u003eProblem 43117. 2D Indexes\u003c/a\u003e\u003c/p\u003e\u003cp\u003eGiven in input the maximum degree P, the algorithm furnishes a ordered list of 3 dimensional vectors [i,j,k] i,j,k\u0026gt;=0 such that i+j+k\u0026lt;=P-1\u003c/p\u003e\u003cpre class=\"language-matlab\"\u003eP=2\r\nindexes=[0,0,0;1,0,0;0,1,0;0,0,1]\r\nP=3\r\nindexes=[0,0,0;1,0,0;0,1,0;0,0,1;2,0,0;1,1,0; 1,0,1; 0,2,0; 0,1,1;0,0,2]\r\n\u003c/pre\u003e","function_template":"function indexes = index3d(P)\r\n  % Good luck\r\nend","test_suite":"%%\r\nP=3;\r\ny_correct =[0,0,0;1,0,0;0,1,0;0,0,1;2,0,0;1,1,0; 1,0,1; 0,2,0; 0,1,1;0,0,2];\r\nassert(isequal(index3d(P),y_correct))\r\n\r\n%% \r\nP=2\r\ny_correct=[0,0,0;1,0,0;0,1,0;0,0,1];\r\nassert(isequal(index3d(P),y_correct))\r\n\r\n%% \r\nP=5\r\ny_correct=[0     0     0;...\r\n     1     0     0;...\r\n     0     1     0;...\r\n     0     0     1;...\r\n     2     0     0;...\r\n     1     1     0;...\r\n     1     0     1;...\r\n     0     2     0;...\r\n     0     1     1;...\r\n     0     0     2;...\r\n     3     0     0;...\r\n     2     1     0;...\r\n     2     0     1;...\r\n     1     2     0;...\r\n     1     1     1;...\r\n     1     0     2;...\r\n     0     3     0;...\r\n     0     2     1;...\r\n     0     1     2;...\r\n     0     0     3;...\r\n     4     0     0;...\r\n     3     1     0;...\r\n     3     0     1;...\r\n     2     2     0;...\r\n     2     1     1;...\r\n     2     0     2;...\r\n     1     3     0;...\r\n     1     2     1;...\r\n     1     1     2;...\r\n     1     0     3;...\r\n     0     4     0;...\r\n     0     3     1;...\r\n     0     2     2;...\r\n     0     1     3;...\r\n     0     0     4;...\r\n         ];\r\n     assert(isequal(index3d(P),y_correct))\r\n\r\n\r\n","published":true,"deleted":false,"likes_count":1,"comments_count":2,"created_by":85837,"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":"2016-10-06T09:09:53.000Z","updated_at":"2026-05-29T01:26:15.000Z","published_at":"2016-10-06T09:09:53.000Z","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\u003eGeneralisation in 3 dimensions of the\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:hyperlink w:docLocation=\\\"http://nl.mathworks.com/matlabcentral/cody/problems/43117-2d-indexes\\\"\u003e\u003cw:r\u003e\u003cw:t\u003eProblem 43117. 2D Indexes\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:hyperlink\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\u003eGiven in input the maximum degree P, the algorithm furnishes a ordered list of 3 dimensional vectors [i,j,k] i,j,k\u0026gt;=0 such that i+j+k\u0026lt;=P-1\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"code\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003e\u003c![CDATA[P=2\\nindexes=[0,0,0;1,0,0;0,1,0;0,0,1]\\nP=3\\nindexes=[0,0,0;1,0,0;0,1,0;0,0,1;2,0,0;1,1,0; 1,0,1; 0,2,0; 0,1,1;0,0,2]]]\u003e\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":{"problems":[{"id":43119,"title":"3D indexes","description":"Generalisation in 3 dimensions of the\r\n\u003chttp://nl.mathworks.com/matlabcentral/cody/problems/43117-2d-indexes Problem 43117. 2D Indexes\u003e\r\n\r\nGiven in input the maximum degree P, the algorithm furnishes a ordered list of 3 dimensional vectors [i,j,k] i,j,k\u003e=0 such that i+j+k\u003c=P-1\r\n\r\n  P=2\r\nindexes=[0,0,0;1,0,0;0,1,0;0,0,1]\r\nP=3\r\nindexes=[0,0,0;1,0,0;0,1,0;0,0,1;2,0,0;1,1,0; 1,0,1; 0,2,0; 0,1,1;0,0,2]\r\n","description_html":"\u003cp\u003eGeneralisation in 3 dimensions of the \u003ca href = \"http://nl.mathworks.com/matlabcentral/cody/problems/43117-2d-indexes\"\u003eProblem 43117. 2D Indexes\u003c/a\u003e\u003c/p\u003e\u003cp\u003eGiven in input the maximum degree P, the algorithm furnishes a ordered list of 3 dimensional vectors [i,j,k] i,j,k\u0026gt;=0 such that i+j+k\u0026lt;=P-1\u003c/p\u003e\u003cpre class=\"language-matlab\"\u003eP=2\r\nindexes=[0,0,0;1,0,0;0,1,0;0,0,1]\r\nP=3\r\nindexes=[0,0,0;1,0,0;0,1,0;0,0,1;2,0,0;1,1,0; 1,0,1; 0,2,0; 0,1,1;0,0,2]\r\n\u003c/pre\u003e","function_template":"function indexes = index3d(P)\r\n  % Good luck\r\nend","test_suite":"%%\r\nP=3;\r\ny_correct =[0,0,0;1,0,0;0,1,0;0,0,1;2,0,0;1,1,0; 1,0,1; 0,2,0; 0,1,1;0,0,2];\r\nassert(isequal(index3d(P),y_correct))\r\n\r\n%% \r\nP=2\r\ny_correct=[0,0,0;1,0,0;0,1,0;0,0,1];\r\nassert(isequal(index3d(P),y_correct))\r\n\r\n%% \r\nP=5\r\ny_correct=[0     0     0;...\r\n     1     0     0;...\r\n     0     1     0;...\r\n     0     0     1;...\r\n     2     0     0;...\r\n     1     1     0;...\r\n     1     0     1;...\r\n     0     2     0;...\r\n     0     1     1;...\r\n     0     0     2;...\r\n     3     0     0;...\r\n     2     1     0;...\r\n     2     0     1;...\r\n     1     2     0;...\r\n     1     1     1;...\r\n     1     0     2;...\r\n     0     3     0;...\r\n     0     2     1;...\r\n     0     1     2;...\r\n     0     0     3;...\r\n     4     0     0;...\r\n     3     1     0;...\r\n     3     0     1;...\r\n     2     2     0;...\r\n     2     1     1;...\r\n     2     0     2;...\r\n     1     3     0;...\r\n     1     2     1;...\r\n     1     1     2;...\r\n     1     0     3;...\r\n     0     4     0;...\r\n     0     3     1;...\r\n     0     2     2;...\r\n     0     1     3;...\r\n     0     0     4;...\r\n         ];\r\n     assert(isequal(index3d(P),y_correct))\r\n\r\n\r\n","published":true,"deleted":false,"likes_count":1,"comments_count":2,"created_by":85837,"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":"2016-10-06T09:09:53.000Z","updated_at":"2026-05-29T01:26:15.000Z","published_at":"2016-10-06T09:09:53.000Z","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\u003eGeneralisation in 3 dimensions of the\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:hyperlink w:docLocation=\\\"http://nl.mathworks.com/matlabcentral/cody/problems/43117-2d-indexes\\\"\u003e\u003cw:r\u003e\u003cw:t\u003eProblem 43117. 2D Indexes\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:hyperlink\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\u003eGiven in input the maximum degree P, the algorithm furnishes a ordered list of 3 dimensional vectors [i,j,k] i,j,k\u0026gt;=0 such that i+j+k\u0026lt;=P-1\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"code\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003e\u003c![CDATA[P=2\\nindexes=[0,0,0;1,0,0;0,1,0;0,0,1]\\nP=3\\nindexes=[0,0,0;1,0,0;0,1,0;0,0,1;2,0,0;1,1,0; 1,0,1; 0,2,0; 0,1,1;0,0,2]]]\u003e\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\"}]}"}],"errors":[],"facets":[[],[{"value":"hard","count":1,"selected":false}]],"term":"tag:\"indexing 3d\"","page":1,"per_page":50,"sort":"map(difficulty_value,0,0,999) asc"}}