{"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":2433,"title":"Consecutive Equation Times (of the day)","description":"Many times throughout the day can represent mathematical equations. In this problem, we focus on the largest consecutive run of equation times that include one of the four basic operations (+,-,*,/) or the power operator (^). Find the largest such consecutive run for a given range of input times (based on three-digit 12-hour times, 1:00 to 9:59). Return the first time stamp (string) and the number of consecutive points (integer, inclusive) for the maximum run (the first run if there is a tie).\r\n\r\nFor example, in the 2:07 to 2:29 time range, the answer is ['2:11' 3] since 2:10 has no equation, 2/1=1 (2:11), 2*1=2 (2:12), 2+1=3 (2:13) and 2:14 has no equation, and there are no such runs of four in that range.\r\n\r\nThis problem is related to \u003chttp://www.mathworks.com/matlabcentral/cody/problems/2431-power-times-of-the-day Problem 2431\u003e and \u003chttp://www.mathworks.com/matlabcentral/cody/problems/2432-equation-times-of-the-day  Problem 2432\u003e.","description_html":"\u003cp\u003eMany times throughout the day can represent mathematical equations. In this problem, we focus on the largest consecutive run of equation times that include one of the four basic operations (+,-,*,/) or the power operator (^). Find the largest such consecutive run for a given range of input times (based on three-digit 12-hour times, 1:00 to 9:59). Return the first time stamp (string) and the number of consecutive points (integer, inclusive) for the maximum run (the first run if there is a tie).\u003c/p\u003e\u003cp\u003eFor example, in the 2:07 to 2:29 time range, the answer is ['2:11' 3] since 2:10 has no equation, 2/1=1 (2:11), 2*1=2 (2:12), 2+1=3 (2:13) and 2:14 has no equation, and there are no such runs of four in that range.\u003c/p\u003e\u003cp\u003eThis problem is related to \u003ca href = \"http://www.mathworks.com/matlabcentral/cody/problems/2431-power-times-of-the-day\"\u003eProblem 2431\u003c/a\u003e and \u003ca href = \"http://www.mathworks.com/matlabcentral/cody/problems/2432-equation-times-of-the-day\"\u003eProblem 2432\u003c/a\u003e.\u003c/p\u003e","function_template":"function [t_s,num] = equation_times_run(times)\r\n t_s = '0:00';\r\n num = 0;\r\nend","test_suite":"%%\r\ntimes = {'1:00' '1:59'};\r\ny_correct = ['1:00' 24];\r\n[t_s,num] = equation_times_run(times);\r\nassert(isequal([t_s,num],y_correct))\r\n\r\n%%\r\ntimes = {'2:07' '2:29'};\r\ny_correct = ['2:11' 3];\r\n[t_s,num] = equation_times_run(times);\r\nassert(isequal([t_s,num],y_correct))\r\n\r\n%%\r\ntimes = {'3:03' '4:04'};\r\ny_correct = ['3:11' 4];\r\n[t_s,num] = equation_times_run(times);\r\nassert(isequal([t_s,num],y_correct))\r\n\r\n%%\r\ntimes = {'5:55' '7:11'};\r\ny_correct = ['6:15' 3];\r\n[t_s,num] = equation_times_run(times);\r\nassert(isequal([t_s,num],y_correct))\r\n\r\n%%\r\ntimes = {'7:17' '9:00'};\r\ny_correct = ['8:17' 3];\r\n[t_s,num] = equation_times_run(times);\r\nassert(isequal([t_s,num],y_correct))\r\n\r\n%%\r\ntimes = {'5:55' '9:00'};\r\ny_correct = ['6:15' 3];\r\n[t_s,num] = equation_times_run(times);\r\nassert(isequal([t_s,num],y_correct))\r\n\r\n%%\r\ntimes = {'1:00' '9:59'};\r\ny_correct = ['1:00' 24];\r\n[t_s,num] = equation_times_run(times);\r\nassert(isequal([t_s,num],y_correct))","published":true,"deleted":false,"likes_count":2,"comments_count":0,"created_by":26769,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":67,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":45,"created_at":"2014-07-15T19:39:50.000Z","updated_at":"2026-05-04T03:34:54.000Z","published_at":"2014-07-15T19:39:50.000Z","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\u003eMany times throughout the day can represent mathematical equations. In this problem, we focus on the largest consecutive run of equation times that include one of the four basic operations (+,-,*,/) or the power operator (^). Find the largest such consecutive run for a given range of input times (based on three-digit 12-hour times, 1:00 to 9:59). Return the first time stamp (string) and the number of consecutive points (integer, inclusive) for the maximum run (the first run if there is a tie).\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\u003eFor example, in the 2:07 to 2:29 time range, the answer is ['2:11' 3] since 2:10 has no equation, 2/1=1 (2:11), 2*1=2 (2:12), 2+1=3 (2:13) and 2:14 has no equation, and there are no such runs of four in that range.\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 problem is related to\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://www.mathworks.com/matlabcentral/cody/problems/2431-power-times-of-the-day\\\"\u003e\u003cw:r\u003e\u003cw:t\u003eProblem 2431\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:hyperlink\u003e\u003cw:r\u003e\u003cw:t\u003e and\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://www.mathworks.com/matlabcentral/cody/problems/2432-equation-times-of-the-day\\\"\u003e\u003cw:r\u003e\u003cw:t\u003eProblem 2432\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:hyperlink\u003e\u003cw:r\u003e\u003cw:t\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\"}]}"},{"id":42323,"title":"With apologies to William Blake","description":"\r\n Coder Coder, typing fast\r\n Sitting at your desk, aghast.\r\n What immortal MATLAB script\r\n will solve this problem, nice and quick?\r\n\r\nYou are given a number. Your task is to write a MATLAB script that will calculate the smallest positive number you need to add to your original number so that each digit in your sum will have horizontal symmetry. For this problem, those numbers are [0 1 3 8]\r\n\r\nFor example:\r\n\r\n*     If you are given 27, your script should output 3, as 27+3=30. Both 3 and 0 have horizontal symmetry.\r\n*     If you are given 801, your script should output 0, as 801+0=801. 8, 0 and 1 are all horizontally symmetric.\r\n*     If you are given 900, your answer should be 100, as 900+100=1000, which is the next highest number that is horizontally symmetric.\r\n\r\nGood luck. May you become a poet, and not even know it.\r\n","description_html":"\u003cpre\u003e Coder Coder, typing fast\r\n Sitting at your desk, aghast.\r\n What immortal MATLAB script\r\n will solve this problem, nice and quick?\u003c/pre\u003e\u003cp\u003eYou are given a number. Your task is to write a MATLAB script that will calculate the smallest positive number you need to add to your original number so that each digit in your sum will have horizontal symmetry. For this problem, those numbers are [0 1 3 8]\u003c/p\u003e\u003cp\u003eFor example:\u003c/p\u003e\u003cul\u003e\u003cli\u003eIf you are given 27, your script should output 3, as 27+3=30. Both 3 and 0 have horizontal symmetry.\u003c/li\u003e\u003cli\u003eIf you are given 801, your script should output 0, as 801+0=801. 8, 0 and 1 are all horizontally symmetric.\u003c/li\u003e\u003cli\u003eIf you are given 900, your answer should be 100, as 900+100=1000, which is the next highest number that is horizontally symmetric.\u003c/li\u003e\u003c/ul\u003e\u003cp\u003eGood luck. May you become a poet, and not even know it.\u003c/p\u003e","function_template":"function y = symmetry(x)\r\n  y = x;\r\nend","test_suite":"%%\r\nassert(isequal(symmetry(27),3))\r\n%%\r\nassert(isequal(symmetry(801),0))\r\n%%\r\nassert(isequal(symmetry(900),100))\r\n%%\r\nassert(isequal(symmetry(88887),1))\r\n%%\r\nassert(isequal(symmetry(1234567),65433))\r\n%%\r\nassert(isequal(symmetry(34567890),3432110))\r\n%%\r\nformat long g\r\nx=ceil(1e9*rand);\r\nj=389e9+x\r\nassert(isequal(8e11-symmetry(j),j))\r\n%%\r\nformat long g\r\nx=ceil(1e10*rand);\r\nj=889e10+x\r\nv=symmetry(j);\r\nassert(isequal(1e13-v,j))\r\n%%\r\nx=2^40-1;\r\nassert(isequal(symmetry(symmetry(symmetry(symmetry(x)))),7775))","published":true,"deleted":false,"likes_count":10,"comments_count":6,"created_by":1615,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":80,"test_suite_updated_at":"2015-05-22T12:38:06.000Z","rescore_all_solutions":false,"group_id":45,"created_at":"2015-05-20T19:03:13.000Z","updated_at":"2026-05-20T05:51:49.000Z","published_at":"2015-05-20T19:09:46.000Z","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=\\\"code\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003e\u003c![CDATA[ Coder Coder, typing fast\\n Sitting at your desk, aghast.\\n What immortal MATLAB script\\n will solve this problem, nice and quick?]]\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\u003eYou are given a number. Your task is to write a MATLAB script that will calculate the smallest positive number you need to add to your original number so that each digit in your sum will have horizontal symmetry. For this problem, those numbers are [0 1 3 8]\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\u003eFor example:\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\u003eIf you are given 27, your script should output 3, as 27+3=30. Both 3 and 0 have horizontal symmetry.\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\u003eIf you are given 801, your script should output 0, as 801+0=801. 8, 0 and 1 are all horizontally symmetric.\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\u003eIf you are given 900, your answer should be 100, as 900+100=1000, which is the next highest number that is horizontally symmetric.\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\u003eGood luck. May you become a poet, and not even know it.\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":2433,"title":"Consecutive Equation Times (of the day)","description":"Many times throughout the day can represent mathematical equations. In this problem, we focus on the largest consecutive run of equation times that include one of the four basic operations (+,-,*,/) or the power operator (^). Find the largest such consecutive run for a given range of input times (based on three-digit 12-hour times, 1:00 to 9:59). Return the first time stamp (string) and the number of consecutive points (integer, inclusive) for the maximum run (the first run if there is a tie).\r\n\r\nFor example, in the 2:07 to 2:29 time range, the answer is ['2:11' 3] since 2:10 has no equation, 2/1=1 (2:11), 2*1=2 (2:12), 2+1=3 (2:13) and 2:14 has no equation, and there are no such runs of four in that range.\r\n\r\nThis problem is related to \u003chttp://www.mathworks.com/matlabcentral/cody/problems/2431-power-times-of-the-day Problem 2431\u003e and \u003chttp://www.mathworks.com/matlabcentral/cody/problems/2432-equation-times-of-the-day  Problem 2432\u003e.","description_html":"\u003cp\u003eMany times throughout the day can represent mathematical equations. In this problem, we focus on the largest consecutive run of equation times that include one of the four basic operations (+,-,*,/) or the power operator (^). Find the largest such consecutive run for a given range of input times (based on three-digit 12-hour times, 1:00 to 9:59). Return the first time stamp (string) and the number of consecutive points (integer, inclusive) for the maximum run (the first run if there is a tie).\u003c/p\u003e\u003cp\u003eFor example, in the 2:07 to 2:29 time range, the answer is ['2:11' 3] since 2:10 has no equation, 2/1=1 (2:11), 2*1=2 (2:12), 2+1=3 (2:13) and 2:14 has no equation, and there are no such runs of four in that range.\u003c/p\u003e\u003cp\u003eThis problem is related to \u003ca href = \"http://www.mathworks.com/matlabcentral/cody/problems/2431-power-times-of-the-day\"\u003eProblem 2431\u003c/a\u003e and \u003ca href = \"http://www.mathworks.com/matlabcentral/cody/problems/2432-equation-times-of-the-day\"\u003eProblem 2432\u003c/a\u003e.\u003c/p\u003e","function_template":"function [t_s,num] = equation_times_run(times)\r\n t_s = '0:00';\r\n num = 0;\r\nend","test_suite":"%%\r\ntimes = {'1:00' '1:59'};\r\ny_correct = ['1:00' 24];\r\n[t_s,num] = equation_times_run(times);\r\nassert(isequal([t_s,num],y_correct))\r\n\r\n%%\r\ntimes = {'2:07' '2:29'};\r\ny_correct = ['2:11' 3];\r\n[t_s,num] = equation_times_run(times);\r\nassert(isequal([t_s,num],y_correct))\r\n\r\n%%\r\ntimes = {'3:03' '4:04'};\r\ny_correct = ['3:11' 4];\r\n[t_s,num] = equation_times_run(times);\r\nassert(isequal([t_s,num],y_correct))\r\n\r\n%%\r\ntimes = {'5:55' '7:11'};\r\ny_correct = ['6:15' 3];\r\n[t_s,num] = equation_times_run(times);\r\nassert(isequal([t_s,num],y_correct))\r\n\r\n%%\r\ntimes = {'7:17' '9:00'};\r\ny_correct = ['8:17' 3];\r\n[t_s,num] = equation_times_run(times);\r\nassert(isequal([t_s,num],y_correct))\r\n\r\n%%\r\ntimes = {'5:55' '9:00'};\r\ny_correct = ['6:15' 3];\r\n[t_s,num] = equation_times_run(times);\r\nassert(isequal([t_s,num],y_correct))\r\n\r\n%%\r\ntimes = {'1:00' '9:59'};\r\ny_correct = ['1:00' 24];\r\n[t_s,num] = equation_times_run(times);\r\nassert(isequal([t_s,num],y_correct))","published":true,"deleted":false,"likes_count":2,"comments_count":0,"created_by":26769,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":67,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":45,"created_at":"2014-07-15T19:39:50.000Z","updated_at":"2026-05-04T03:34:54.000Z","published_at":"2014-07-15T19:39:50.000Z","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\u003eMany times throughout the day can represent mathematical equations. In this problem, we focus on the largest consecutive run of equation times that include one of the four basic operations (+,-,*,/) or the power operator (^). Find the largest such consecutive run for a given range of input times (based on three-digit 12-hour times, 1:00 to 9:59). Return the first time stamp (string) and the number of consecutive points (integer, inclusive) for the maximum run (the first run if there is a tie).\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\u003eFor example, in the 2:07 to 2:29 time range, the answer is ['2:11' 3] since 2:10 has no equation, 2/1=1 (2:11), 2*1=2 (2:12), 2+1=3 (2:13) and 2:14 has no equation, and there are no such runs of four in that range.\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 problem is related to\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://www.mathworks.com/matlabcentral/cody/problems/2431-power-times-of-the-day\\\"\u003e\u003cw:r\u003e\u003cw:t\u003eProblem 2431\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:hyperlink\u003e\u003cw:r\u003e\u003cw:t\u003e and\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://www.mathworks.com/matlabcentral/cody/problems/2432-equation-times-of-the-day\\\"\u003e\u003cw:r\u003e\u003cw:t\u003eProblem 2432\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:hyperlink\u003e\u003cw:r\u003e\u003cw:t\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\"}]}"},{"id":42323,"title":"With apologies to William Blake","description":"\r\n Coder Coder, typing fast\r\n Sitting at your desk, aghast.\r\n What immortal MATLAB script\r\n will solve this problem, nice and quick?\r\n\r\nYou are given a number. Your task is to write a MATLAB script that will calculate the smallest positive number you need to add to your original number so that each digit in your sum will have horizontal symmetry. For this problem, those numbers are [0 1 3 8]\r\n\r\nFor example:\r\n\r\n*     If you are given 27, your script should output 3, as 27+3=30. Both 3 and 0 have horizontal symmetry.\r\n*     If you are given 801, your script should output 0, as 801+0=801. 8, 0 and 1 are all horizontally symmetric.\r\n*     If you are given 900, your answer should be 100, as 900+100=1000, which is the next highest number that is horizontally symmetric.\r\n\r\nGood luck. May you become a poet, and not even know it.\r\n","description_html":"\u003cpre\u003e Coder Coder, typing fast\r\n Sitting at your desk, aghast.\r\n What immortal MATLAB script\r\n will solve this problem, nice and quick?\u003c/pre\u003e\u003cp\u003eYou are given a number. Your task is to write a MATLAB script that will calculate the smallest positive number you need to add to your original number so that each digit in your sum will have horizontal symmetry. For this problem, those numbers are [0 1 3 8]\u003c/p\u003e\u003cp\u003eFor example:\u003c/p\u003e\u003cul\u003e\u003cli\u003eIf you are given 27, your script should output 3, as 27+3=30. Both 3 and 0 have horizontal symmetry.\u003c/li\u003e\u003cli\u003eIf you are given 801, your script should output 0, as 801+0=801. 8, 0 and 1 are all horizontally symmetric.\u003c/li\u003e\u003cli\u003eIf you are given 900, your answer should be 100, as 900+100=1000, which is the next highest number that is horizontally symmetric.\u003c/li\u003e\u003c/ul\u003e\u003cp\u003eGood luck. May you become a poet, and not even know it.\u003c/p\u003e","function_template":"function y = symmetry(x)\r\n  y = x;\r\nend","test_suite":"%%\r\nassert(isequal(symmetry(27),3))\r\n%%\r\nassert(isequal(symmetry(801),0))\r\n%%\r\nassert(isequal(symmetry(900),100))\r\n%%\r\nassert(isequal(symmetry(88887),1))\r\n%%\r\nassert(isequal(symmetry(1234567),65433))\r\n%%\r\nassert(isequal(symmetry(34567890),3432110))\r\n%%\r\nformat long g\r\nx=ceil(1e9*rand);\r\nj=389e9+x\r\nassert(isequal(8e11-symmetry(j),j))\r\n%%\r\nformat long g\r\nx=ceil(1e10*rand);\r\nj=889e10+x\r\nv=symmetry(j);\r\nassert(isequal(1e13-v,j))\r\n%%\r\nx=2^40-1;\r\nassert(isequal(symmetry(symmetry(symmetry(symmetry(x)))),7775))","published":true,"deleted":false,"likes_count":10,"comments_count":6,"created_by":1615,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":80,"test_suite_updated_at":"2015-05-22T12:38:06.000Z","rescore_all_solutions":false,"group_id":45,"created_at":"2015-05-20T19:03:13.000Z","updated_at":"2026-05-20T05:51:49.000Z","published_at":"2015-05-20T19:09:46.000Z","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=\\\"code\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003e\u003c![CDATA[ Coder Coder, typing fast\\n Sitting at your desk, aghast.\\n What immortal MATLAB script\\n will solve this problem, nice and quick?]]\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\u003eYou are given a number. Your task is to write a MATLAB script that will calculate the smallest positive number you need to add to your original number so that each digit in your sum will have horizontal symmetry. For this problem, those numbers are [0 1 3 8]\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\u003eFor example:\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\u003eIf you are given 27, your script should output 3, as 27+3=30. Both 3 and 0 have horizontal symmetry.\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\u003eIf you are given 801, your script should output 0, as 801+0=801. 8, 0 and 1 are all horizontally symmetric.\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\u003eIf you are given 900, your answer should be 100, as 900+100=1000, which is the next highest number that is horizontally symmetric.\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\u003eGood luck. 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