{"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":1167,"title":"matrix zigzag","description":"Unfold a 2-D matrix to a 1-D array in zig-zag order, e.g., for matrix\r\n\r\n [ 1 2 3 ;\r\n   4 5 6 ;\r\n   7 8 9 ] \r\n\r\nthe resulting 1-D array should be \r\n\r\n [ 1 2 4 7 5 3 6 8 9 ]","description_html":"\u003cp\u003eUnfold a 2-D matrix to a 1-D array in zig-zag order, e.g., for matrix\u003c/p\u003e\u003cpre\u003e [ 1 2 3 ;\r\n   4 5 6 ;\r\n   7 8 9 ] \u003c/pre\u003e\u003cp\u003ethe resulting 1-D array should be\u003c/p\u003e\u003cpre\u003e [ 1 2 4 7 5 3 6 8 9 ]\u003c/pre\u003e","function_template":"function y = zigzag(x)\r\n  y = x;\r\nend","test_suite":"%%\r\nx = [1 2; 3 4];\r\ny_correct = [1 2 3 4];\r\nassert(isequal(zigzag(x),y_correct))\r\n\r\n%%\r\nx = [ 1 2 3; 4 5 6; 7 8 9];\r\ny_correct = [ 1 2 4 7 5 3 6 8 9];\r\nassert(isequal(zigzag(x),y_correct))\r\n\r\n%%\r\nx = magic(4);\r\ny_correct = [16 2 5 9 11 3 13 10 7 4 14 6 8 12 15 1];\r\nassert(isequal(zigzag(x),y_correct))","published":true,"deleted":false,"likes_count":12,"comments_count":0,"created_by":9535,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":353,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":23,"created_at":"2013-01-04T03:24:14.000Z","updated_at":"2026-05-26T14:56:06.000Z","published_at":"2013-01-04T03:24:30.000Z","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\u003eUnfold a 2-D matrix to a 1-D array in zig-zag order, e.g., for matrix\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[ [ 1 2 3 ;\\n   4 5 6 ;\\n   7 8 9 ]]]\u003e\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\u003ethe resulting 1-D array should be\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[ [ 1 2 4 7 5 3 6 8 9 ]]]\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":1167,"title":"matrix zigzag","description":"Unfold a 2-D matrix to a 1-D array in zig-zag order, e.g., for matrix\r\n\r\n [ 1 2 3 ;\r\n   4 5 6 ;\r\n   7 8 9 ] \r\n\r\nthe resulting 1-D array should be \r\n\r\n [ 1 2 4 7 5 3 6 8 9 ]","description_html":"\u003cp\u003eUnfold a 2-D matrix to a 1-D array in zig-zag order, e.g., for matrix\u003c/p\u003e\u003cpre\u003e [ 1 2 3 ;\r\n   4 5 6 ;\r\n   7 8 9 ] \u003c/pre\u003e\u003cp\u003ethe resulting 1-D array should be\u003c/p\u003e\u003cpre\u003e [ 1 2 4 7 5 3 6 8 9 ]\u003c/pre\u003e","function_template":"function y = zigzag(x)\r\n  y = x;\r\nend","test_suite":"%%\r\nx = [1 2; 3 4];\r\ny_correct = [1 2 3 4];\r\nassert(isequal(zigzag(x),y_correct))\r\n\r\n%%\r\nx = [ 1 2 3; 4 5 6; 7 8 9];\r\ny_correct = [ 1 2 4 7 5 3 6 8 9];\r\nassert(isequal(zigzag(x),y_correct))\r\n\r\n%%\r\nx = magic(4);\r\ny_correct = [16 2 5 9 11 3 13 10 7 4 14 6 8 12 15 1];\r\nassert(isequal(zigzag(x),y_correct))","published":true,"deleted":false,"likes_count":12,"comments_count":0,"created_by":9535,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":353,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":23,"created_at":"2013-01-04T03:24:14.000Z","updated_at":"2026-05-26T14:56:06.000Z","published_at":"2013-01-04T03:24:30.000Z","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\u003eUnfold a 2-D matrix to a 1-D array in zig-zag order, e.g., for matrix\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[ [ 1 2 3 ;\\n   4 5 6 ;\\n   7 8 9 ]]]\u003e\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\u003ethe resulting 1-D array should be\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[ [ 1 2 4 7 5 3 6 8 9 ]]]\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":"Matrix Manipulation II","count":1,"selected":false}],[{"value":"medium","count":1,"selected":false}]],"term":"tag:\"compression.\"","page":1,"per_page":50,"sort":"map(difficulty_value,0,0,999) asc"}}