{"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":776,"title":"TRON strategy toggle","description":"Detect whether your lightcycle is on same side of existing walls as opponents lightcycle. This function is useful in toggling a tron algorithm from agressive/strategic mode (chasing and hassling opponent) to passive/efficiency mode (wherein you'd presumably focus on using up remaining space, and wouldn't have to bother tracking opponent, etc.). Inspired by Alfonso Nieto-Castanon's Problem 327, as well as Richard Zapor's followups.\r\ninput: 50 by 50 matrix of lightcycle and wall positions, empty space = 0, lightcycles = 1 \u0026 2, outer walls = -3, lightcycle trails/walls = -1 and -2.\r\noutput: true if on same side, or false if no path exists between the two light cycles.","description_html":"\u003cdiv style = \"text-align: start; line-height: 20.4333px; 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: rgb(0, 0, 0); white-space: normal; \"\u003e\u003cdiv style=\"block-size: 165px; display: block; min-width: 0px; padding-block-start: 0px; padding-top: 0px; perspective-origin: 406.5px 82.5px; transform-origin: 406.5px 82.5px; vertical-align: baseline; \"\u003e\u003cdiv style=\"block-size: 84px; 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: 383.5px 42px; text-align: left; transform-origin: 383.5px 42px; white-space: pre-wrap; 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: 365.8px 7.75px; transform-origin: 365.8px 7.75px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eDetect whether your lightcycle is on same side of existing walls as opponents lightcycle. This function is useful in toggling a tron algorithm from agressive/strategic mode (chasing and hassling opponent) to passive/efficiency mode (wherein you'd presumably focus on using up remaining space, and wouldn't have to bother tracking opponent, etc.). Inspired by Alfonso Nieto-Castanon's\u003c/span\u003e\u003c/span\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: 2.06667px 7.75px; transform-origin: 2.06667px 7.75px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003e \u003c/span\u003e\u003c/span\u003e\u003ca target='_blank' href = \"/#null\"\u003e\u003cspan style=\"\"\u003e\u003cspan style=\"\"\u003eProblem 327\u003c/span\u003e\u003c/span\u003e\u003c/a\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: 123.483px 7.75px; transform-origin: 123.483px 7.75px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003e, as well as Richard Zapor's followups.\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 42px; 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: 383.5px 21px; text-align: left; transform-origin: 383.5px 21px; white-space: pre-wrap; 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: 380.267px 7.75px; transform-origin: 380.267px 7.75px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003einput: 50 by 50 matrix of lightcycle and wall positions, empty space = 0, lightcycles = 1 \u0026amp; 2, outer walls = -3, lightcycle trails/walls = -1 and -2.\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: 383.5px 10.5px; text-align: left; transform-origin: 383.5px 10.5px; white-space: pre-wrap; 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: 264.533px 7.75px; transform-origin: 264.533px 7.75px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eoutput: true if on same side, or false if no path exists between the two light cycles.\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e","function_template":"function y = onSameSide(board)\r\n  y = true;\r\nend","test_suite":"%%\r\nboard=zeros(50);\r\nboard([1,end],:)=-3;\r\nboard(:,[1,end])=-3;\r\nboard(2,2) = 1;\r\nboard(49,49)=2;\r\ny_correct = true;\r\nassert(isequal(onSameSide(board),y_correct))\r\n%%\r\nboard=zeros(50);\r\nboard([1,end],:)=-3;\r\nboard(:,[1,end])=-3;\r\nboard(5,25) = 1;\r\nboard(46,25)=2;\r\nboard(25,2:49)=-2;\r\ny_correct = false;\r\nassert(isequal(onSameSide(board),y_correct))\r\n%%\r\nboard=zeros(50);\r\nboard([1,end],:)=-3;\r\nboard(:,[1,end])=-3;\r\nboard(5,25) = 1;\r\nboard(46,25)=2;\r\nboard(28,2:48)=-2;\r\nboard(23,3:49)=-1;\r\ny_correct = true;\r\nassert(isequal(onSameSide(board),y_correct))\r\n\r\n%%\r\n%diagonal walls\r\nboard=-eye(50);\r\nboard([1,end],:)=-3;\r\nboard(:,[1,end])=-3;\r\nboard(5,25) = 1;\r\nboard(46,25)=2;\r\ny_correct = false;\r\nassert(isequal(onSameSide(board),y_correct))\r\n\r\n%%\r\n%diagonal walls\r\nboard=-eye(50);\r\nboard([1,end],:)=-3;\r\nboard(:,[1,end])=-3;\r\nidx=randi([2 20])\r\nboard(idx,idx+1)=1;\r\nboard(idx,idx-1)=2;\r\ny_correct = false;\r\nassert(isequal(onSameSide(board),y_correct))\r\n\r\n\r\n%%\r\n%diagonal walls\r\nboard=-rot90(eye(50));\r\nboard([1,end],:)=-3;\r\nboard(:,[1,end])=-3;\r\nboard(5,25)=1;\r\nboard(46,25)=2;\r\ny_correct = false;\r\nassert(isequal(onSameSide(board),y_correct))","published":true,"deleted":false,"likes_count":2,"comments_count":4,"created_by":2846,"edited_by":223089,"edited_at":"2023-03-03T11:47:35.000Z","deleted_by":null,"deleted_at":null,"solvers_count":26,"test_suite_updated_at":"2023-03-03T11:47:35.000Z","rescore_all_solutions":false,"group_id":1,"created_at":"2012-06-19T20:11:09.000Z","updated_at":"2026-03-31T15:12:08.000Z","published_at":"2012-06-19T20:11:09.000Z","restored_at":null,"restored_by":null,"spam":null,"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\u003eDetect whether your lightcycle is on same side of existing walls as opponents lightcycle. This function is useful in toggling a tron algorithm from agressive/strategic mode (chasing and hassling opponent) to passive/efficiency mode (wherein you'd presumably focus on using up remaining space, and wouldn't have to bother tracking opponent, etc.). Inspired by Alfonso Nieto-Castanon's\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=\\\"\\\"\u003e\u003cw:r\u003e\u003cw:t\u003eProblem 327\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:hyperlink\u003e\u003cw:r\u003e\u003cw:t\u003e, as well as Richard Zapor's followups.\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\u003einput: 50 by 50 matrix of lightcycle and wall positions, empty space = 0, lightcycles = 1 \u0026amp; 2, outer walls = -3, lightcycle trails/walls = -1 and -2.\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\u003eoutput: true if on same side, or false if no path exists between the two light cycles.\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":776,"title":"TRON strategy toggle","description":"Detect whether your lightcycle is on same side of existing walls as opponents lightcycle. This function is useful in toggling a tron algorithm from agressive/strategic mode (chasing and hassling opponent) to passive/efficiency mode (wherein you'd presumably focus on using up remaining space, and wouldn't have to bother tracking opponent, etc.). Inspired by Alfonso Nieto-Castanon's Problem 327, as well as Richard Zapor's followups.\r\ninput: 50 by 50 matrix of lightcycle and wall positions, empty space = 0, lightcycles = 1 \u0026 2, outer walls = -3, lightcycle trails/walls = -1 and -2.\r\noutput: true if on same side, or false if no path exists between the two light cycles.","description_html":"\u003cdiv style = \"text-align: start; line-height: 20.4333px; 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: rgb(0, 0, 0); white-space: normal; \"\u003e\u003cdiv style=\"block-size: 165px; display: block; min-width: 0px; padding-block-start: 0px; padding-top: 0px; perspective-origin: 406.5px 82.5px; transform-origin: 406.5px 82.5px; vertical-align: baseline; \"\u003e\u003cdiv style=\"block-size: 84px; 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: 383.5px 42px; text-align: left; transform-origin: 383.5px 42px; white-space: pre-wrap; 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: 365.8px 7.75px; transform-origin: 365.8px 7.75px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eDetect whether your lightcycle is on same side of existing walls as opponents lightcycle. This function is useful in toggling a tron algorithm from agressive/strategic mode (chasing and hassling opponent) to passive/efficiency mode (wherein you'd presumably focus on using up remaining space, and wouldn't have to bother tracking opponent, etc.). Inspired by Alfonso Nieto-Castanon's\u003c/span\u003e\u003c/span\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: 2.06667px 7.75px; transform-origin: 2.06667px 7.75px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003e \u003c/span\u003e\u003c/span\u003e\u003ca target='_blank' href = \"/#null\"\u003e\u003cspan style=\"\"\u003e\u003cspan style=\"\"\u003eProblem 327\u003c/span\u003e\u003c/span\u003e\u003c/a\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: 123.483px 7.75px; transform-origin: 123.483px 7.75px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003e, as well as Richard Zapor's followups.\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 42px; 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: 383.5px 21px; text-align: left; transform-origin: 383.5px 21px; white-space: pre-wrap; 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: 380.267px 7.75px; transform-origin: 380.267px 7.75px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003einput: 50 by 50 matrix of lightcycle and wall positions, empty space = 0, lightcycles = 1 \u0026amp; 2, outer walls = -3, lightcycle trails/walls = -1 and -2.\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: 383.5px 10.5px; text-align: left; transform-origin: 383.5px 10.5px; white-space: pre-wrap; 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: 264.533px 7.75px; transform-origin: 264.533px 7.75px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eoutput: true if on same side, or false if no path exists between the two light cycles.\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e","function_template":"function y = onSameSide(board)\r\n  y = true;\r\nend","test_suite":"%%\r\nboard=zeros(50);\r\nboard([1,end],:)=-3;\r\nboard(:,[1,end])=-3;\r\nboard(2,2) = 1;\r\nboard(49,49)=2;\r\ny_correct = true;\r\nassert(isequal(onSameSide(board),y_correct))\r\n%%\r\nboard=zeros(50);\r\nboard([1,end],:)=-3;\r\nboard(:,[1,end])=-3;\r\nboard(5,25) = 1;\r\nboard(46,25)=2;\r\nboard(25,2:49)=-2;\r\ny_correct = false;\r\nassert(isequal(onSameSide(board),y_correct))\r\n%%\r\nboard=zeros(50);\r\nboard([1,end],:)=-3;\r\nboard(:,[1,end])=-3;\r\nboard(5,25) = 1;\r\nboard(46,25)=2;\r\nboard(28,2:48)=-2;\r\nboard(23,3:49)=-1;\r\ny_correct = true;\r\nassert(isequal(onSameSide(board),y_correct))\r\n\r\n%%\r\n%diagonal walls\r\nboard=-eye(50);\r\nboard([1,end],:)=-3;\r\nboard(:,[1,end])=-3;\r\nboard(5,25) = 1;\r\nboard(46,25)=2;\r\ny_correct = false;\r\nassert(isequal(onSameSide(board),y_correct))\r\n\r\n%%\r\n%diagonal walls\r\nboard=-eye(50);\r\nboard([1,end],:)=-3;\r\nboard(:,[1,end])=-3;\r\nidx=randi([2 20])\r\nboard(idx,idx+1)=1;\r\nboard(idx,idx-1)=2;\r\ny_correct = false;\r\nassert(isequal(onSameSide(board),y_correct))\r\n\r\n\r\n%%\r\n%diagonal walls\r\nboard=-rot90(eye(50));\r\nboard([1,end],:)=-3;\r\nboard(:,[1,end])=-3;\r\nboard(5,25)=1;\r\nboard(46,25)=2;\r\ny_correct = false;\r\nassert(isequal(onSameSide(board),y_correct))","published":true,"deleted":false,"likes_count":2,"comments_count":4,"created_by":2846,"edited_by":223089,"edited_at":"2023-03-03T11:47:35.000Z","deleted_by":null,"deleted_at":null,"solvers_count":26,"test_suite_updated_at":"2023-03-03T11:47:35.000Z","rescore_all_solutions":false,"group_id":1,"created_at":"2012-06-19T20:11:09.000Z","updated_at":"2026-03-31T15:12:08.000Z","published_at":"2012-06-19T20:11:09.000Z","restored_at":null,"restored_by":null,"spam":null,"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\u003eDetect whether your lightcycle is on same side of existing walls as opponents lightcycle. This function is useful in toggling a tron algorithm from agressive/strategic mode (chasing and hassling opponent) to passive/efficiency mode (wherein you'd presumably focus on using up remaining space, and wouldn't have to bother tracking opponent, etc.). Inspired by Alfonso Nieto-Castanon's\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=\\\"\\\"\u003e\u003cw:r\u003e\u003cw:t\u003eProblem 327\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:hyperlink\u003e\u003cw:r\u003e\u003cw:t\u003e, as well as Richard Zapor's followups.\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\u003einput: 50 by 50 matrix of lightcycle and wall positions, empty space = 0, lightcycles = 1 \u0026amp; 2, outer walls = -3, lightcycle trails/walls = -1 and -2.\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\u003eoutput: true if on same side, or false if no path exists between the two light cycles.\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":"The Movies","count":1,"selected":false}],[{"value":"medium","count":1,"selected":false}]],"term":"tag:\"tron\"","page":1,"per_page":50,"sort":"map(difficulty_value,0,0,999) asc"}}