{"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":42307,"title":"Long-digit Subtraction","description":"Suppose you need to subtract a very large integer from another integer. \u003chttp://www.mathworks.com/matlabcentral/cody/problems/563-how-to-add This problem\u003e requires the player to add two long digits, both supplied as strings, and to return the sum as a string. This problem similarly provides two numbers as strings and you must return the difference as a string (a - b = c). The result will always be positive as a will be larger than b. See the test suite for examples.\r\n","description_html":"\u003cp\u003eSuppose you need to subtract a very large integer from another integer. \u003ca href = \"http://www.mathworks.com/matlabcentral/cody/problems/563-how-to-add\"\u003eThis problem\u003c/a\u003e requires the player to add two long digits, both supplied as strings, and to return the sum as a string. This problem similarly provides two numbers as strings and you must return the difference as a string (a - b = c). The result will always be positive as a will be larger than b. See the test suite for examples.\u003c/p\u003e","function_template":"function c = long_digit_subtraction(a,b)\r\n\r\nc = a - b;\r\n\r\nend\r\n","test_suite":"%%\r\na = '99999';\r\nb = '87654';\r\n%----------\r\nc = '12345';\r\nassert(strcmp(long_digit_subtraction(a,b),c))\r\n\r\n%%\r\na = '99999';\r\nb =  '1234';\r\n%----------\r\nc = '98765';\r\nassert(strcmp(long_digit_subtraction(a,b),c))\r\n\r\n%%\r\na = '99999';\r\nb = '98765';\r\n%----------\r\nc =  '1234';\r\nassert(strcmp(long_digit_subtraction(a,b),c))\r\n\r\n%%\r\na = '99999';\r\nb = '90909';\r\n%----------\r\nc =  '9090';\r\nassert(strcmp(long_digit_subtraction(a,b),c))\r\n\r\n%%\r\na = '11111';\r\nb =  '1234';\r\n%----------\r\nc =  '9877';\r\nassert(strcmp(long_digit_subtraction(a,b),c))\r\n\r\n%%\r\na = '10000';\r\nb =     '1';\r\n%----------\r\nc =  '9999';\r\nassert(strcmp(long_digit_subtraction(a,b),c))\r\n\r\n%%\r\na = '10000000';\r\nb =  '9999999';\r\n%-------------\r\nc =        '1';\r\nassert(strcmp(long_digit_subtraction(a,b),c))\r\n\r\n%%\r\na = '100000000000000000000000000000000000000000000000000000000000000000000';\r\nb =                                                                     '1';\r\n%--------------------------------------------------------------------------\r\nc =  '99999999999999999999999999999999999999999999999999999999999999999999';\r\nassert(strcmp(long_digit_subtraction(a,b),c))\r\n\r\n%%\r\na = '2135476542136876516521651162516';\r\nb =  '165267982494266414654661818517';\r\n%------------------------------------\r\nc = '1970208559642610101866989343999';\r\nassert(strcmp(long_digit_subtraction(a,b),c))\r\n\r\n%%\r\na = '1000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000';\r\nb =                                                                                                                                                             '1';\r\n%------------------------------------------------------------------------------------------------------------------------------------------------------------------\r\nc =  '999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999';\r\nassert(strcmp(long_digit_subtraction(a,b),c))\r\n\r\n%%\r\na = '1000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000';\r\nb =                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             '1';\r\n%------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------\r\nc =  '999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999';\r\nassert(strcmp(long_digit_subtraction(a,b),c))\r\n\r\n%%\r\nswitch randi(4)\r\n\tcase 1\r\n\t\ta = '99999';\r\n\t\tb = '87654';\r\n\t\tc = '12345';\r\n\tcase 2\r\n\t\ta = '99999';\r\n\t\tb =  '1234';\r\n\t\tc = '98765';\r\n\tcase 3\r\n\t\ta = '10000000';\r\n\t\tb =  '9999999';\r\n\t\tc =        '1';\r\n\tcase 4\r\n\t\ta = '99999';\r\n\t\tb = '90909';\r\n\t\tc =  '9090';\r\nend\r\nassert(strcmp(long_digit_subtraction(a,b),c))\r\n\r\n%%\r\nswitch randi(4)\r\n\tcase 1\r\n\t\ta = '99999';\r\n\t\tb = '98765';\r\n\t\tc =  '1234';\r\n\tcase 2\r\n\t\ta = '10000';\r\n\t\tb =     '1';\r\n\t\tc =  '9999';\r\n\tcase 3\r\n\t\ta = '99999';\r\n\t\tb = '87654';\r\n\t\tc = '12345';\r\n\tcase 4\r\n\t\ta = '2135476542136876516521651162516';\r\n\t\tb =  '165267982494266414654661818517';\r\n\t\tc = '1970208559642610101866989343999';\r\nend\r\nassert(strcmp(long_digit_subtraction(a,b),c))\r\n\r\n%%\r\nswitch randi(4)\r\n\tcase 1\r\n\t\ta = '11111';\r\n\t\tb =  '1234';\r\n\t\tc =  '9877';\r\n\tcase 2\r\n\t\ta = '10000000';\r\n\t\tb =  '9999999';\r\n\t\tc =        '1';\r\n\tcase 3\r\n\t\ta = '99999';\r\n\t\tb = '98765';\r\n\t\tc =  '1234';\r\n\tcase 4\r\n\t\ta = '99999';\r\n\t\tb = '87654';\r\n\t\tc = '12345';\r\nend\r\nassert(strcmp(long_digit_subtraction(a,b),c))\r\n","published":true,"deleted":false,"likes_count":0,"comments_count":0,"created_by":26769,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":25,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":1,"created_at":"2015-05-13T01:27:00.000Z","updated_at":"2026-05-28T13:38:54.000Z","published_at":"2015-05-13T01:27:00.000Z","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\u003eSuppose you need to subtract a very large integer from another integer.\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/563-how-to-add\\\"\u003e\u003cw:r\u003e\u003cw:t\u003eThis problem\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:hyperlink\u003e\u003cw:r\u003e\u003cw:t\u003e requires the player to add two long digits, both supplied as strings, and to return the sum as a string. This problem similarly provides two numbers as strings and you must return the difference as a string (a - b = c). The result will always be positive as a will be larger than b. See the test suite for examples.\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":42307,"title":"Long-digit Subtraction","description":"Suppose you need to subtract a very large integer from another integer. \u003chttp://www.mathworks.com/matlabcentral/cody/problems/563-how-to-add This problem\u003e requires the player to add two long digits, both supplied as strings, and to return the sum as a string. This problem similarly provides two numbers as strings and you must return the difference as a string (a - b = c). The result will always be positive as a will be larger than b. See the test suite for examples.\r\n","description_html":"\u003cp\u003eSuppose you need to subtract a very large integer from another integer. \u003ca href = \"http://www.mathworks.com/matlabcentral/cody/problems/563-how-to-add\"\u003eThis problem\u003c/a\u003e requires the player to add two long digits, both supplied as strings, and to return the sum as a string. This problem similarly provides two numbers as strings and you must return the difference as a string (a - b = c). The result will always be positive as a will be larger than b. See the test suite for examples.\u003c/p\u003e","function_template":"function c = long_digit_subtraction(a,b)\r\n\r\nc = a - b;\r\n\r\nend\r\n","test_suite":"%%\r\na = '99999';\r\nb = '87654';\r\n%----------\r\nc = '12345';\r\nassert(strcmp(long_digit_subtraction(a,b),c))\r\n\r\n%%\r\na = '99999';\r\nb =  '1234';\r\n%----------\r\nc = '98765';\r\nassert(strcmp(long_digit_subtraction(a,b),c))\r\n\r\n%%\r\na = '99999';\r\nb = '98765';\r\n%----------\r\nc =  '1234';\r\nassert(strcmp(long_digit_subtraction(a,b),c))\r\n\r\n%%\r\na = '99999';\r\nb = '90909';\r\n%----------\r\nc =  '9090';\r\nassert(strcmp(long_digit_subtraction(a,b),c))\r\n\r\n%%\r\na = '11111';\r\nb =  '1234';\r\n%----------\r\nc =  '9877';\r\nassert(strcmp(long_digit_subtraction(a,b),c))\r\n\r\n%%\r\na = '10000';\r\nb =     '1';\r\n%----------\r\nc =  '9999';\r\nassert(strcmp(long_digit_subtraction(a,b),c))\r\n\r\n%%\r\na = '10000000';\r\nb =  '9999999';\r\n%-------------\r\nc =        '1';\r\nassert(strcmp(long_digit_subtraction(a,b),c))\r\n\r\n%%\r\na = '100000000000000000000000000000000000000000000000000000000000000000000';\r\nb =                                                                     '1';\r\n%--------------------------------------------------------------------------\r\nc =  '99999999999999999999999999999999999999999999999999999999999999999999';\r\nassert(strcmp(long_digit_subtraction(a,b),c))\r\n\r\n%%\r\na = '2135476542136876516521651162516';\r\nb =  '165267982494266414654661818517';\r\n%------------------------------------\r\nc = '1970208559642610101866989343999';\r\nassert(strcmp(long_digit_subtraction(a,b),c))\r\n\r\n%%\r\na = '1000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000';\r\nb =                                                                                                                                                             '1';\r\n%------------------------------------------------------------------------------------------------------------------------------------------------------------------\r\nc =  '999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999';\r\nassert(strcmp(long_digit_subtraction(a,b),c))\r\n\r\n%%\r\na = '1000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000';\r\nb =                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             '1';\r\n%------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------\r\nc =  '999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999';\r\nassert(strcmp(long_digit_subtraction(a,b),c))\r\n\r\n%%\r\nswitch randi(4)\r\n\tcase 1\r\n\t\ta = '99999';\r\n\t\tb = '87654';\r\n\t\tc = '12345';\r\n\tcase 2\r\n\t\ta = '99999';\r\n\t\tb =  '1234';\r\n\t\tc = '98765';\r\n\tcase 3\r\n\t\ta = '10000000';\r\n\t\tb =  '9999999';\r\n\t\tc =        '1';\r\n\tcase 4\r\n\t\ta = '99999';\r\n\t\tb = '90909';\r\n\t\tc =  '9090';\r\nend\r\nassert(strcmp(long_digit_subtraction(a,b),c))\r\n\r\n%%\r\nswitch randi(4)\r\n\tcase 1\r\n\t\ta = '99999';\r\n\t\tb = '98765';\r\n\t\tc =  '1234';\r\n\tcase 2\r\n\t\ta = '10000';\r\n\t\tb =     '1';\r\n\t\tc =  '9999';\r\n\tcase 3\r\n\t\ta = '99999';\r\n\t\tb = '87654';\r\n\t\tc = '12345';\r\n\tcase 4\r\n\t\ta = '2135476542136876516521651162516';\r\n\t\tb =  '165267982494266414654661818517';\r\n\t\tc = '1970208559642610101866989343999';\r\nend\r\nassert(strcmp(long_digit_subtraction(a,b),c))\r\n\r\n%%\r\nswitch randi(4)\r\n\tcase 1\r\n\t\ta = '11111';\r\n\t\tb =  '1234';\r\n\t\tc =  '9877';\r\n\tcase 2\r\n\t\ta = '10000000';\r\n\t\tb =  '9999999';\r\n\t\tc =        '1';\r\n\tcase 3\r\n\t\ta = '99999';\r\n\t\tb = '98765';\r\n\t\tc =  '1234';\r\n\tcase 4\r\n\t\ta = '99999';\r\n\t\tb = '87654';\r\n\t\tc = '12345';\r\nend\r\nassert(strcmp(long_digit_subtraction(a,b),c))\r\n","published":true,"deleted":false,"likes_count":0,"comments_count":0,"created_by":26769,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":25,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":1,"created_at":"2015-05-13T01:27:00.000Z","updated_at":"2026-05-28T13:38:54.000Z","published_at":"2015-05-13T01:27:00.000Z","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\u003eSuppose you need to subtract a very large integer from another integer.\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/563-how-to-add\\\"\u003e\u003cw:r\u003e\u003cw:t\u003eThis problem\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:hyperlink\u003e\u003cw:r\u003e\u003cw:t\u003e requires the player to add two long digits, both supplied as strings, and to return the sum as a string. This problem similarly provides two numbers as strings and you must return the difference as a string (a - b = c). The result will always be positive as a will be larger than b. See the test suite for examples.\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":"medium","count":1,"selected":false}]],"term":"tag:\"long-digit\"","page":1,"per_page":50,"sort":"map(difficulty_value,0,0,999) asc"}}