{"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":60416,"title":"Secret Message and Acrostic","description":"One of the simplest ways to hide a message involves utilizing uppercase letters.\r\nGiven a text, collect all uppercase letters into a single word, maintaining their order of appearance in the text. For instance: \r\ntext = 'Lorem ipsum dolor sit amet, consectetur adipiscing elit. Integer nec odio. Praesent libero.'\r\nBy gathering all the uppercase letters, the hidden message becomes \"LIP\".","description_html":"\u003cdiv style = \"text-align: start; line-height: 20.44px; min-height: 0px; white-space: normal; color: rgb(0, 0, 0); font-family: Menlo, Monaco, Consolas, monospace; font-style: normal; font-size: 14px; font-weight: 400; text-decoration: none solid rgb(0, 0, 0); white-space: normal; \"\u003e\u003cdiv style=\"block-size: 111px; display: block; min-width: 0px; padding-block-start: 0px; padding-top: 0px; perspective-origin: 407px 55.5px; transform-origin: 407px 55.5px; vertical-align: baseline; \"\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space-collapse: preserve; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 0px 0px; transform-origin: 0px 0px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eOne of the simplest ways to hide a message involves utilizing uppercase letters.\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space-collapse: preserve; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 0px 0px; transform-origin: 0px 0px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eGiven a text, collect all uppercase letters into a single word, maintaining their order of appearance in the text. For instance: \u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space-collapse: preserve; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 0px 0px; transform-origin: 0px 0px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003etext = 'Lorem ipsum dolor sit amet, consectetur adipiscing elit. Integer nec odio. Praesent libero.'\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space-collapse: preserve; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 0px 0px; transform-origin: 0px 0px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eBy gathering all the uppercase letters, the hidden message becomes \"LIP\".\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e","function_template":"function secret_message = find_message(text)\r\n\r\nend","test_suite":"%%\r\ntext = 'Lorem ipsum dolor sit amet, consectetur adipiscing elit. Integer nec odio. Praesent libero.';\r\nmsg = find_message(text)\r\nmsg_correct = 'LIP'\r\nassert(isequal(msg,msg_correct));\r\n%% EMPTY\r\ntext = 'text'\r\nmsg = find_message(text)\r\nassert(isempty(msg));\r\n%%\r\ntext = 'Cuddly Acrobatic Tenacious and terrifying Softly purring'\r\nmsg = find_message(text)\r\nmsg_correct = 'CATS'\r\nassert(isequal(msg,msg_correct));\r\n%%\r\ntext = 'How are you? Eh, ok. Low or Lower? Ohhh.'\r\nmsg = find_message(text)\r\nmsg_correct = 'HELLO'\r\nassert(isequal(msg,msg_correct));\r\n%% \r\ntext = 'Secret, sEcret, seCret, secRet, secrEt, secreT!'\r\nmsg = find_message(text)\r\nmsg_correct = 'SECRET'\r\nassert(isequal(msg,msg_correct));\r\n%% Random 1\r\nn = randi([4, 15]); \r\nalphabet = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'; \r\nmsg_correct = alphabet(randi(numel(alphabet), 1, n));\r\ntext = '';\r\nfor i = 1:n\r\n    for j = 1:n\r\n        if j == i\r\n            text = [text upper(msg_correct(j))];\r\n        else\r\n            text = [text lower(msg_correct(j))];\r\n        end\r\n    end\r\n    text = [text ' '];\r\nend\r\ntext\r\nmsg = find_message(text)\r\nmsg_correct\r\nassert(isequal(msg,msg_correct));\r\n%% Random 2\r\ntext = 'this is an example of a sentence with random uppercase letters.' ;\r\nuppercase_indices = unique(randi([1, length(text)-1],1,10));\r\nmsg_correct = '';\r\nfor i = uppercase_indices\r\n    if isletter(text(i))\r\n        L = upper(text(i));\r\n        text(i) = L;\r\n        msg_correct = strcat(msg_correct,L);\r\n    end\r\nend\r\ntext\r\nmsg = find_message(text)\r\nmsg_correct\r\nassert(isequal(msg,msg_correct));\r\n\r\n","published":true,"deleted":false,"likes_count":0,"comments_count":2,"created_by":208445,"edited_by":208445,"edited_at":"2024-06-04T13:07:10.000Z","deleted_by":null,"deleted_at":null,"solvers_count":14,"test_suite_updated_at":"2024-06-04T13:07:10.000Z","rescore_all_solutions":false,"group_id":1,"created_at":"2024-06-02T09:44:43.000Z","updated_at":"2026-03-16T11:11:08.000Z","published_at":"2024-06-02T09:51:06.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"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\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eOne of the simplest ways to hide a message involves utilizing uppercase letters.\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\u003eGiven a text, collect all uppercase letters into a single word, maintaining their order of appearance in the text. For instance: \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\u003etext = 'Lorem ipsum dolor sit amet, consectetur adipiscing elit. Integer nec odio. Praesent libero.'\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\u003eBy gathering all the uppercase letters, the hidden message becomes \\\"LIP\\\".\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\",\"relationship\":null}],\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"target\":\"/matlab/document.xml\",\"relationshipId\":\"rId1\"}]}"}],"problem_search":{"problems":[{"id":60416,"title":"Secret Message and Acrostic","description":"One of the simplest ways to hide a message involves utilizing uppercase letters.\r\nGiven a text, collect all uppercase letters into a single word, maintaining their order of appearance in the text. For instance: \r\ntext = 'Lorem ipsum dolor sit amet, consectetur adipiscing elit. Integer nec odio. Praesent libero.'\r\nBy gathering all the uppercase letters, the hidden message becomes \"LIP\".","description_html":"\u003cdiv style = \"text-align: start; line-height: 20.44px; min-height: 0px; white-space: normal; color: rgb(0, 0, 0); font-family: Menlo, Monaco, Consolas, monospace; font-style: normal; font-size: 14px; font-weight: 400; text-decoration: none solid rgb(0, 0, 0); white-space: normal; \"\u003e\u003cdiv style=\"block-size: 111px; display: block; min-width: 0px; padding-block-start: 0px; padding-top: 0px; perspective-origin: 407px 55.5px; transform-origin: 407px 55.5px; vertical-align: baseline; \"\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space-collapse: preserve; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 0px 0px; transform-origin: 0px 0px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eOne of the simplest ways to hide a message involves utilizing uppercase letters.\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space-collapse: preserve; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 0px 0px; transform-origin: 0px 0px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eGiven a text, collect all uppercase letters into a single word, maintaining their order of appearance in the text. For instance: \u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space-collapse: preserve; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 0px 0px; transform-origin: 0px 0px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003etext = 'Lorem ipsum dolor sit amet, consectetur adipiscing elit. Integer nec odio. Praesent libero.'\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space-collapse: preserve; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 0px 0px; transform-origin: 0px 0px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eBy gathering all the uppercase letters, the hidden message becomes \"LIP\".\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e","function_template":"function secret_message = find_message(text)\r\n\r\nend","test_suite":"%%\r\ntext = 'Lorem ipsum dolor sit amet, consectetur adipiscing elit. Integer nec odio. Praesent libero.';\r\nmsg = find_message(text)\r\nmsg_correct = 'LIP'\r\nassert(isequal(msg,msg_correct));\r\n%% EMPTY\r\ntext = 'text'\r\nmsg = find_message(text)\r\nassert(isempty(msg));\r\n%%\r\ntext = 'Cuddly Acrobatic Tenacious and terrifying Softly purring'\r\nmsg = find_message(text)\r\nmsg_correct = 'CATS'\r\nassert(isequal(msg,msg_correct));\r\n%%\r\ntext = 'How are you? Eh, ok. Low or Lower? Ohhh.'\r\nmsg = find_message(text)\r\nmsg_correct = 'HELLO'\r\nassert(isequal(msg,msg_correct));\r\n%% \r\ntext = 'Secret, sEcret, seCret, secRet, secrEt, secreT!'\r\nmsg = find_message(text)\r\nmsg_correct = 'SECRET'\r\nassert(isequal(msg,msg_correct));\r\n%% Random 1\r\nn = randi([4, 15]); \r\nalphabet = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'; \r\nmsg_correct = alphabet(randi(numel(alphabet), 1, n));\r\ntext = '';\r\nfor i = 1:n\r\n    for j = 1:n\r\n        if j == i\r\n            text = [text upper(msg_correct(j))];\r\n        else\r\n            text = [text lower(msg_correct(j))];\r\n        end\r\n    end\r\n    text = [text ' '];\r\nend\r\ntext\r\nmsg = find_message(text)\r\nmsg_correct\r\nassert(isequal(msg,msg_correct));\r\n%% Random 2\r\ntext = 'this is an example of a sentence with random uppercase letters.' ;\r\nuppercase_indices = unique(randi([1, length(text)-1],1,10));\r\nmsg_correct = '';\r\nfor i = uppercase_indices\r\n    if isletter(text(i))\r\n        L = upper(text(i));\r\n        text(i) = L;\r\n        msg_correct = strcat(msg_correct,L);\r\n    end\r\nend\r\ntext\r\nmsg = find_message(text)\r\nmsg_correct\r\nassert(isequal(msg,msg_correct));\r\n\r\n","published":true,"deleted":false,"likes_count":0,"comments_count":2,"created_by":208445,"edited_by":208445,"edited_at":"2024-06-04T13:07:10.000Z","deleted_by":null,"deleted_at":null,"solvers_count":14,"test_suite_updated_at":"2024-06-04T13:07:10.000Z","rescore_all_solutions":false,"group_id":1,"created_at":"2024-06-02T09:44:43.000Z","updated_at":"2026-03-16T11:11:08.000Z","published_at":"2024-06-02T09:51:06.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"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\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eOne of the simplest ways to hide a message involves utilizing uppercase letters.\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\u003eGiven a text, collect all uppercase letters into a single word, maintaining their order of appearance in the text. For instance: \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\u003etext = 'Lorem ipsum dolor sit amet, consectetur adipiscing elit. Integer nec odio. Praesent libero.'\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\u003eBy gathering all the uppercase letters, the hidden message becomes \\\"LIP\\\".\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\",\"relationship\":null}],\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"target\":\"/matlab/document.xml\",\"relationshipId\":\"rId1\"}]}"}],"errors":[],"facets":[[],[{"value":"easy","count":1,"selected":false}]],"term":"tag:\"acrostic\"","page":1,"per_page":50,"sort":"map(difficulty_value,0,0,999) asc"}}