{"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":44324,"title":"Rewrite setdiff to account for non-unique values","description":"Setdiff(a,b) is a function that will remove all values of b from a.  Sometimes, you need this function to do a little bit extra, though.  Write a newer version of setdiff that will take into account numbers appearing multiple times in a.  For example:\r\n\r\na=[8 7 6 5 4 3 2 1 1];\r\nb=[1 3 4 5 6 7];\r\n\r\nIn this example, setdiff(a,b) would return [2 8], since only 2 and 8 are not included in a.  However, there are two \"1\" values in a, and only one \"1\" in b, so new_setdiff should return [1 2 8].  Your output vector should be sorted from low to high.\r\n\r\nYou can assume that there are no Inf or NaN in either vector, and that no values will appear in b more times than will appear in a.\r\n","description_html":"\u003cp\u003eSetdiff(a,b) is a function that will remove all values of b from a.  Sometimes, you need this function to do a little bit extra, though.  Write a newer version of setdiff that will take into account numbers appearing multiple times in a.  For example:\u003c/p\u003e\u003cp\u003ea=[8 7 6 5 4 3 2 1 1];\r\nb=[1 3 4 5 6 7];\u003c/p\u003e\u003cp\u003eIn this example, setdiff(a,b) would return [2 8], since only 2 and 8 are not included in a.  However, there are two \"1\" values in a, and only one \"1\" in b, so new_setdiff should return [1 2 8].  Your output vector should be sorted from low to high.\u003c/p\u003e\u003cp\u003eYou can assume that there are no Inf or NaN in either vector, and that no values will appear in b more times than will appear in a.\u003c/p\u003e","function_template":"function y = new_setdiff(a,b)\r\n  y = [a,b];\r\nend","test_suite":"%%\r\na=[1 1 2 3 4 5 6 7 8]; b=[1 3 4 5 6 7];\r\ny_correct=[1 2 8];\r\nassert(isequal(new_setdiff(a,b),y_correct))\r\nassert(isequal(new_setdiff(fliplr(a),b),y_correct))\r\nassert(isequal(new_setdiff(a,fliplr(b)),y_correct))\r\n%%\r\na=repmat([1:10],1,2);\r\nb=repmat([1:5],1,2);\r\ny_correct=[6 6 7 7 8 8 9 9 10 10];\r\nassert(isequal(new_setdiff(a,b),y_correct))\r\n%%\r\na=[randperm(10) 3 5 7];\r\nb=randperm(6)+1;\r\ny_correct=[1 3 5 7 8 9 10];\r\nassert(isequal(new_setdiff(a,b),y_correct))\r\n%%\r\na=[-5:5 -4:4];\r\nb=[-4:4];\r\ny_correct=[-5:5]\r\nassert(isequal(new_setdiff(a,b),y_correct))\r\n%%\r\na=[2 2 2 2 3 3 5 7];\r\nb=[2 2 2 2 3 3 5];\r\ny_correct=8;\r\nassert(isequal(new_setdiff(a,b),y_correct-1))\r\n%%\r\na=[21 124 23 20 21 23 124];\r\nb=[20 21 21 23 23];\r\ny_correct=[124 124]\r\nassert(isequal(new_setdiff(a,b),y_correct))\r\n","published":true,"deleted":false,"likes_count":0,"comments_count":0,"created_by":1615,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":34,"test_suite_updated_at":"2018-01-02T15:45:30.000Z","rescore_all_solutions":true,"group_id":1,"created_at":"2017-09-14T16:19:26.000Z","updated_at":"2026-05-25T00:59:16.000Z","published_at":"2017-09-14T16:19:26.000Z","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\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"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\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\u003eSetdiff(a,b) is a function that will remove all values of b from a. Sometimes, you need this function to do a little bit extra, though. Write a newer version of setdiff that will take into account numbers appearing multiple times in a. For example:\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003ea=[8 7 6 5 4 3 2 1 1]; b=[1 3 4 5 6 7];\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eIn this example, setdiff(a,b) would return [2 8], since only 2 and 8 are not included in a. However, there are two \\\"1\\\" values in a, and only one \\\"1\\\" in b, so new_setdiff should return [1 2 8]. Your output vector should be sorted from low to high.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eYou can assume that there are no Inf or NaN in either vector, and that no values will appear in b more times than will appear in a.\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":44324,"title":"Rewrite setdiff to account for non-unique values","description":"Setdiff(a,b) is a function that will remove all values of b from a.  Sometimes, you need this function to do a little bit extra, though.  Write a newer version of setdiff that will take into account numbers appearing multiple times in a.  For example:\r\n\r\na=[8 7 6 5 4 3 2 1 1];\r\nb=[1 3 4 5 6 7];\r\n\r\nIn this example, setdiff(a,b) would return [2 8], since only 2 and 8 are not included in a.  However, there are two \"1\" values in a, and only one \"1\" in b, so new_setdiff should return [1 2 8].  Your output vector should be sorted from low to high.\r\n\r\nYou can assume that there are no Inf or NaN in either vector, and that no values will appear in b more times than will appear in a.\r\n","description_html":"\u003cp\u003eSetdiff(a,b) is a function that will remove all values of b from a.  Sometimes, you need this function to do a little bit extra, though.  Write a newer version of setdiff that will take into account numbers appearing multiple times in a.  For example:\u003c/p\u003e\u003cp\u003ea=[8 7 6 5 4 3 2 1 1];\r\nb=[1 3 4 5 6 7];\u003c/p\u003e\u003cp\u003eIn this example, setdiff(a,b) would return [2 8], since only 2 and 8 are not included in a.  However, there are two \"1\" values in a, and only one \"1\" in b, so new_setdiff should return [1 2 8].  Your output vector should be sorted from low to high.\u003c/p\u003e\u003cp\u003eYou can assume that there are no Inf or NaN in either vector, and that no values will appear in b more times than will appear in a.\u003c/p\u003e","function_template":"function y = new_setdiff(a,b)\r\n  y = [a,b];\r\nend","test_suite":"%%\r\na=[1 1 2 3 4 5 6 7 8]; b=[1 3 4 5 6 7];\r\ny_correct=[1 2 8];\r\nassert(isequal(new_setdiff(a,b),y_correct))\r\nassert(isequal(new_setdiff(fliplr(a),b),y_correct))\r\nassert(isequal(new_setdiff(a,fliplr(b)),y_correct))\r\n%%\r\na=repmat([1:10],1,2);\r\nb=repmat([1:5],1,2);\r\ny_correct=[6 6 7 7 8 8 9 9 10 10];\r\nassert(isequal(new_setdiff(a,b),y_correct))\r\n%%\r\na=[randperm(10) 3 5 7];\r\nb=randperm(6)+1;\r\ny_correct=[1 3 5 7 8 9 10];\r\nassert(isequal(new_setdiff(a,b),y_correct))\r\n%%\r\na=[-5:5 -4:4];\r\nb=[-4:4];\r\ny_correct=[-5:5]\r\nassert(isequal(new_setdiff(a,b),y_correct))\r\n%%\r\na=[2 2 2 2 3 3 5 7];\r\nb=[2 2 2 2 3 3 5];\r\ny_correct=8;\r\nassert(isequal(new_setdiff(a,b),y_correct-1))\r\n%%\r\na=[21 124 23 20 21 23 124];\r\nb=[20 21 21 23 23];\r\ny_correct=[124 124]\r\nassert(isequal(new_setdiff(a,b),y_correct))\r\n","published":true,"deleted":false,"likes_count":0,"comments_count":0,"created_by":1615,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":34,"test_suite_updated_at":"2018-01-02T15:45:30.000Z","rescore_all_solutions":true,"group_id":1,"created_at":"2017-09-14T16:19:26.000Z","updated_at":"2026-05-25T00:59:16.000Z","published_at":"2017-09-14T16:19:26.000Z","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\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"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\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\u003eSetdiff(a,b) is a function that will remove all values of b from a. Sometimes, you need this function to do a little bit extra, though. Write a newer version of setdiff that will take into account numbers appearing multiple times in a. For example:\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003ea=[8 7 6 5 4 3 2 1 1]; b=[1 3 4 5 6 7];\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eIn this example, setdiff(a,b) would return [2 8], since only 2 and 8 are not included in a. However, there are two \\\"1\\\" values in a, and only one \\\"1\\\" in b, so new_setdiff should return [1 2 8]. Your output vector should be sorted from low to high.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eYou can assume that there are no Inf or NaN in either vector, and that no values will appear in b more times than will appear in a.\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":"Functions II","count":1,"selected":false}],[{"value":"medium","count":1,"selected":false}]],"term":"tag:\"setdiff\"","page":1,"per_page":50,"sort":"map(difficulty_value,0,0,999) asc"}}