{"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":1985,"title":"How unique?","description":"Sometimes, when we check unique entries of vector we would like to know how many times each value occurs.\r\n\r\nGiven vector of numbers *A* return vector *U* of unique values of A and corresponding vector *H* with occurrences.\r\n\r\nExample:\r\n\r\n   in:  A = [2 2 2 3 3 2 3 8 6 5 6]\r\n  out:  U = [2 3 8 6 5]\r\n        H = [4 3 1 2 1]  ","description_html":"\u003cp\u003eSometimes, when we check unique entries of vector we would like to know how many times each value occurs.\u003c/p\u003e\u003cp\u003eGiven vector of numbers \u003cb\u003eA\u003c/b\u003e return vector \u003cb\u003eU\u003c/b\u003e of unique values of A and corresponding vector \u003cb\u003eH\u003c/b\u003e with occurrences.\u003c/p\u003e\u003cp\u003eExample:\u003c/p\u003e\u003cpre\u003e   in:  A = [2 2 2 3 3 2 3 8 6 5 6]\r\n  out:  U = [2 3 8 6 5]\r\n        H = [4 3 1 2 1]  \u003c/pre\u003e","function_template":"function [U,H] = hunique(A)\r\n  U = 1:5;\r\n  H = ones(1,5);\r\nend","test_suite":"%%\r\nA = [2 2 2 3 3 2 3 8 6 5 6];\r\n[U, H] = hunique(A);\r\nU_ok = [2 3 8 6 5];\r\nH_ok = [4 3 1 2 1];\r\nassert(isequal(U,U_ok));\r\nassert(isequal(H,H_ok));\r\n%%\r\nA = [2 2 2 3 3 2 3 8 6 5 6 8];\r\n[U, H] = hunique(A);\r\nU_ok = [2 3 8 6 5];\r\nH_ok = [4 3 2 2 1];\r\nassert(isequal(U,U_ok));\r\nassert(isequal(H,H_ok));\r\n%%\r\nA = 100:-11:1;\r\nassert(isequal(hunique(A),A));\r\n[~,H] = hunique(A);\r\nassert(isequal(H,ones(1,10)));\r\n%%\r\nA = randi([-10 10],1,100);\r\n[U,H] = hunique(A);\r\nassert(sum(H)==numel(A));\r\nassert(isequal(unique(A),sort(U)));\r\n\r\n% number of test cases may increace in the future.\r\n% any proposals of test cases warmly welcome.","published":true,"deleted":false,"likes_count":1,"comments_count":0,"created_by":14358,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":140,"test_suite_updated_at":"2014-04-06T18:52:22.000Z","rescore_all_solutions":false,"group_id":21,"created_at":"2013-11-12T23:00:10.000Z","updated_at":"2026-05-05T20:00:31.000Z","published_at":"2013-11-13T23:40:01.000Z","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\u003eSometimes, when we check unique entries of vector we would like to know how many times each value occurs.\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\u003eGiven vector of numbers\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:b/\u003e\u003c/w:rPr\u003e\u003cw:t\u003eA\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e return vector\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:b/\u003e\u003c/w:rPr\u003e\u003cw:t\u003eU\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e of unique values of A and corresponding vector\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:b/\u003e\u003c/w:rPr\u003e\u003cw:t\u003eH\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e with occurrences.\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\u003eExample:\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[   in:  A = [2 2 2 3 3 2 3 8 6 5 6]\\n  out:  U = [2 3 8 6 5]\\n        H = [4 3 1 2 1]]]\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":1985,"title":"How unique?","description":"Sometimes, when we check unique entries of vector we would like to know how many times each value occurs.\r\n\r\nGiven vector of numbers *A* return vector *U* of unique values of A and corresponding vector *H* with occurrences.\r\n\r\nExample:\r\n\r\n   in:  A = [2 2 2 3 3 2 3 8 6 5 6]\r\n  out:  U = [2 3 8 6 5]\r\n        H = [4 3 1 2 1]  ","description_html":"\u003cp\u003eSometimes, when we check unique entries of vector we would like to know how many times each value occurs.\u003c/p\u003e\u003cp\u003eGiven vector of numbers \u003cb\u003eA\u003c/b\u003e return vector \u003cb\u003eU\u003c/b\u003e of unique values of A and corresponding vector \u003cb\u003eH\u003c/b\u003e with occurrences.\u003c/p\u003e\u003cp\u003eExample:\u003c/p\u003e\u003cpre\u003e   in:  A = [2 2 2 3 3 2 3 8 6 5 6]\r\n  out:  U = [2 3 8 6 5]\r\n        H = [4 3 1 2 1]  \u003c/pre\u003e","function_template":"function [U,H] = hunique(A)\r\n  U = 1:5;\r\n  H = ones(1,5);\r\nend","test_suite":"%%\r\nA = [2 2 2 3 3 2 3 8 6 5 6];\r\n[U, H] = hunique(A);\r\nU_ok = [2 3 8 6 5];\r\nH_ok = [4 3 1 2 1];\r\nassert(isequal(U,U_ok));\r\nassert(isequal(H,H_ok));\r\n%%\r\nA = [2 2 2 3 3 2 3 8 6 5 6 8];\r\n[U, H] = hunique(A);\r\nU_ok = [2 3 8 6 5];\r\nH_ok = [4 3 2 2 1];\r\nassert(isequal(U,U_ok));\r\nassert(isequal(H,H_ok));\r\n%%\r\nA = 100:-11:1;\r\nassert(isequal(hunique(A),A));\r\n[~,H] = hunique(A);\r\nassert(isequal(H,ones(1,10)));\r\n%%\r\nA = randi([-10 10],1,100);\r\n[U,H] = hunique(A);\r\nassert(sum(H)==numel(A));\r\nassert(isequal(unique(A),sort(U)));\r\n\r\n% number of test cases may increace in the future.\r\n% any proposals of test cases warmly welcome.","published":true,"deleted":false,"likes_count":1,"comments_count":0,"created_by":14358,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":140,"test_suite_updated_at":"2014-04-06T18:52:22.000Z","rescore_all_solutions":false,"group_id":21,"created_at":"2013-11-12T23:00:10.000Z","updated_at":"2026-05-05T20:00:31.000Z","published_at":"2013-11-13T23:40:01.000Z","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\u003eSometimes, when we check unique entries of vector we would like to know how many times each value occurs.\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\u003eGiven vector of numbers\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:b/\u003e\u003c/w:rPr\u003e\u003cw:t\u003eA\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e return vector\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:b/\u003e\u003c/w:rPr\u003e\u003cw:t\u003eU\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e of unique values of A and corresponding vector\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:b/\u003e\u003c/w:rPr\u003e\u003cw:t\u003eH\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e with occurrences.\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\u003eExample:\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[   in:  A = [2 2 2 3 3 2 3 8 6 5 6]\\n  out:  U = [2 3 8 6 5]\\n        H = [4 3 1 2 1]]]\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":"Indexing III","count":1,"selected":false}],[{"value":"medium","count":1,"selected":false}]],"term":"tag:\"uniqueness\"","page":1,"per_page":50,"sort":"map(difficulty_value,0,0,999) asc"}}