{"trustable":true,"prependHtml":"\u003cstyle\u003e.statText pre { font-size: 12px; }\ntable {display:block !important; width:100%; }\ntable tbody {display:block !important; width:100%; }\ntable tbody tr { width:100% !important;display: block;}\ntable tbody tr td.statText { margin-left: 5px; display: inline-block; width: fit-content; }\ntable tbody tr td.statText br { display: block; content: \" \";line-height: 12px;margin: 12px 0;}\ntable tbody tr td.statText table table pre {\n white-space: pre-wrap;\n text-overflow: ellipsis;\n word-break: break-all;\n}\ntd { padding: 0 !important; border: none !important; }\npre { line-height: normal; margin: 0; }\n\u003c/style\u003e","sections":[{"title":"","value":{"format":"HTML","content":"\n \n \t\t\u003ctable\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd colspan\u003d\"2\" class\u003d\"statText\"\u003e\u003ch3\u003eProblem Statement\u003c/h3\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd class\u003d\"statText\"\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u003c/td\u003e\u003ctd class\u003d\"statText\"\u003e\u003cp\u003eCat Snuke and wolf Sothe are playing the Connecting Game.\u003c/p\u003e\n\u003cbr\u003e\u003cp\u003eThe Connecting Game is played on a rectangular grid that is divided into unit square cells.\nThe grid is divided into some regions.\nEach cell belongs into exactly one of those regions.\nEach region is 4-connected (see Notes for a formal definition).\u003c/p\u003e\n\u003cbr\u003e\u003cp\u003eYou are given a String[] \u003cb\u003eboard\u003c/b\u003e that describes the division of the grid into regions.\nEach character in \u003cb\u003eboard\u003c/b\u003e represents one of the cells.\nCells that are represented by the same character belong into the same region.\u003c/p\u003e\n\u003cbr\u003e\u003cp\u003eInitially, the entire grid is colorless.\nDuring the game, the players color some of the regions red and other regions blue.\n(Within each region, all cells must have the same color.)\nThe game ends when the entire board is colored.\nThe actual rules of the game are not important.\nThe only information you need is that at the end of the game each combination of red and blue regions is possible.\u003c/p\u003e\n\u003cbr\u003e\u003cp\u003eAt the end, the game is evaluated as follows:\u003c/p\u003e\n\u003cul\u003e\n\u003cli\u003eIf there is a path (see Notes for a formal definition) of blue cells from the top row to the bottom row, Snuke wins.\u003c/li\u003e\n\u003cli\u003eIf there is a path of red cells from the left column to the right column, Sothe wins.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cbr\u003e\u003cp\u003eObviously, it is impossible for both players to win the game at the same time.\nHowever, sometimes there can be no winner.\nYour task is to recognize game boards for which this may happen.\u003c/p\u003e\n\u003cbr\u003e\u003cp\u003eFormally, a board is called \u003ci\u003evalid\u003c/i\u003e if it is guaranteed that the game will have a winner, and \u003ci\u003einvalid\u003c/i\u003e if it is possible that there is no winner at the end of the game.\nYou are given the String[] \u003cb\u003eboard\u003c/b\u003e.\nReturn \"valid\" (quotes for clarity) if it represents a valid board, or \"invalid\" if it does not.\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan\u003d\"2\" class\u003d\"statText\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan\u003d\"2\" class\u003d\"statText\"\u003e\u003ch3\u003eDefinition\u003c/h3\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd class\u003d\"statText\"\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u003c/td\u003e\u003ctd class\u003d\"statText\"\u003e\u003ctable\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd class\u003d\"statText\"\u003eClass:\u003c/td\u003e\u003ctd class\u003d\"statText\"\u003eConnectingGame\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd class\u003d\"statText\"\u003eMethod:\u003c/td\u003e\u003ctd class\u003d\"statText\"\u003eisValid\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd class\u003d\"statText\"\u003eParameters:\u003c/td\u003e\u003ctd class\u003d\"statText\"\u003eString[]\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd class\u003d\"statText\"\u003eReturns:\u003c/td\u003e\u003ctd class\u003d\"statText\"\u003eString\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd class\u003d\"statText\"\u003eMethod signature:\u003c/td\u003e\u003ctd class\u003d\"statText\"\u003eString isValid(String[] board)\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan\u003d\"2\" class\u003d\"statText\"\u003e(be sure your method is public)\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd class\u003d\"statText\"\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd class\u003d\"statText\"\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan\u003d\"2\" class\u003d\"statText\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan\u003d\"2\" class\u003d\"statText\"\u003e\u003ch3\u003eNotes\u003c/h3\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align\u003d\"center\" valign\u003d\"top\" class\u003d\"statText\"\u003e-\u003c/td\u003e\u003ctd class\u003d\"statText\"\u003eA path is a sequence of cells such that each pair of consecutive cells shares a common side.\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align\u003d\"center\" valign\u003d\"top\" class\u003d\"statText\"\u003e-\u003c/td\u003e\u003ctd class\u003d\"statText\"\u003eA region is 4-connected if for any two cells A and B in that region there is a path that starts with A, ends with B, and only contains cells from that region.\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan\u003d\"2\" class\u003d\"statText\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan\u003d\"2\" class\u003d\"statText\"\u003e\u003ch3\u003eConstraints\u003c/h3\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align\u003d\"center\" valign\u003d\"top\" class\u003d\"statText\"\u003e-\u003c/td\u003e\u003ctd class\u003d\"statText\"\u003e\u003cb\u003eboard\u003c/b\u003e will contain between 1 and 30 elements, inclusive.\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align\u003d\"center\" valign\u003d\"top\" class\u003d\"statText\"\u003e-\u003c/td\u003e\u003ctd class\u003d\"statText\"\u003eEach element in \u003cb\u003eboard\u003c/b\u003e will contain between 1 and 30 characters, inclusive.\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align\u003d\"center\" valign\u003d\"top\" class\u003d\"statText\"\u003e-\u003c/td\u003e\u003ctd class\u003d\"statText\"\u003eAll elements in \u003cb\u003eboard\u003c/b\u003e will have the same length.\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align\u003d\"center\" valign\u003d\"top\" class\u003d\"statText\"\u003e-\u003c/td\u003e\u003ctd class\u003d\"statText\"\u003eEach character in \u003cb\u003eboard\u003c/b\u003e will be a letter or a digit (\u0027a\u0027-\u0027z\u0027, \u0027A\u0027-\u0027Z\u0027, or \u00270\u0027-\u00279\u0027).\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align\u003d\"center\" valign\u003d\"top\" class\u003d\"statText\"\u003e-\u003c/td\u003e\u003ctd class\u003d\"statText\"\u003eEach of the regions in \u003cb\u003eboard\u003c/b\u003e will be 4-connected.\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan\u003d\"2\" class\u003d\"statText\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan\u003d\"2\" class\u003d\"statText\"\u003e\u003ch3\u003eExamples\u003c/h3\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align\u003d\"center\" nowrap\u003d\"true\" class\u003d\"statText\"\u003e0)\u003c/td\u003e\u003ctd class\u003d\"statText\"\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd class\u003d\"statText\"\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u003c/td\u003e\u003ctd class\u003d\"statText\"\u003e\u003ctable\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd class\u003d\"statText\"\u003e\u003ctable\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd class\u003d\"statText\"\u003e\u003cpre\u003e{\"AAB\"\n,\"CCD\"}\u003c/pre\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd class\u003d\"statText\"\u003e\u003cpre\u003eReturns: \"invalid\"\u003c/pre\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd class\u003d\"statText\"\u003e\u003ctable\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd colspan\u003d\"2\" class\u003d\"statText\"\u003eIf the players color regions A and D red and regions B and C blue, no player wins. Hence, this board is invalid.\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align\u003d\"center\" nowrap\u003d\"true\" class\u003d\"statText\"\u003e1)\u003c/td\u003e\u003ctd class\u003d\"statText\"\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd class\u003d\"statText\"\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u003c/td\u003e\u003ctd class\u003d\"statText\"\u003e\u003ctable\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd class\u003d\"statText\"\u003e\u003ctable\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd class\u003d\"statText\"\u003e\u003cpre\u003e{\"AA\"\n,\"BB\"}\u003c/pre\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd class\u003d\"statText\"\u003e\u003cpre\u003eReturns: \"valid\"\u003c/pre\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd class\u003d\"statText\"\u003e\u003ctable\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd colspan\u003d\"2\" class\u003d\"statText\"\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align\u003d\"center\" nowrap\u003d\"true\" class\u003d\"statText\"\u003e2)\u003c/td\u003e\u003ctd class\u003d\"statText\"\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd class\u003d\"statText\"\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u003c/td\u003e\u003ctd class\u003d\"statText\"\u003e\u003ctable\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd class\u003d\"statText\"\u003e\u003ctable\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd class\u003d\"statText\"\u003e\u003cpre\u003e{\"iii\"\n,\"iwi\"\n,\"iii\"}\u003c/pre\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd class\u003d\"statText\"\u003e\u003cpre\u003eReturns: \"valid\"\u003c/pre\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd class\u003d\"statText\"\u003e\u003ctable\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd colspan\u003d\"2\" class\u003d\"statText\"\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align\u003d\"center\" nowrap\u003d\"true\" class\u003d\"statText\"\u003e3)\u003c/td\u003e\u003ctd class\u003d\"statText\"\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd class\u003d\"statText\"\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u003c/td\u003e\u003ctd class\u003d\"statText\"\u003e\u003ctable\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd class\u003d\"statText\"\u003e\u003ctable\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd class\u003d\"statText\"\u003e\u003cpre\u003e{\"SSnukee\"\n,\"SKnuthe\"\n,\"SSSothe\"}\u003c/pre\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd class\u003d\"statText\"\u003e\u003cpre\u003eReturns: \"invalid\"\u003c/pre\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd class\u003d\"statText\"\u003e\u003ctable\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd colspan\u003d\"2\" class\u003d\"statText\"\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align\u003d\"center\" nowrap\u003d\"true\" class\u003d\"statText\"\u003e4)\u003c/td\u003e\u003ctd class\u003d\"statText\"\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd class\u003d\"statText\"\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u003c/td\u003e\u003ctd class\u003d\"statText\"\u003e\u003ctable\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd class\u003d\"statText\"\u003e\u003ctable\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd class\u003d\"statText\"\u003e\u003cpre\u003e{\"rng58\"\n,\"rnggn\"\n,\"rnnnn\"}\u003c/pre\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd class\u003d\"statText\"\u003e\u003cpre\u003eReturns: \"valid\"\u003c/pre\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd class\u003d\"statText\"\u003e\u003ctable\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd colspan\u003d\"2\" class\u003d\"statText\"\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align\u003d\"center\" nowrap\u003d\"true\" class\u003d\"statText\"\u003e5)\u003c/td\u003e\u003ctd class\u003d\"statText\"\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd class\u003d\"statText\"\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u003c/td\u003e\u003ctd class\u003d\"statText\"\u003e\u003ctable\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd class\u003d\"statText\"\u003e\u003ctable\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd class\u003d\"statText\"\u003e\u003cpre\u003e{\"ggssGGGGGG\",\"ggssspGGGG\",\"ggsssppGGG\",\"ggWsspGGGG\",\"gggsspGGiG\",\"g7ssspGGGG\",\"gggsseKK33\",\"gggssssK33\",\"gHgsssHA33\",\"HHHHHHHHHH\",\"HHHHHHHHH6\",\"HHHHHHHHb6\"}\u003c/pre\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd class\u003d\"statText\"\u003e\u003cpre\u003eReturns: \"invalid\"\u003c/pre\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd class\u003d\"statText\"\u003e\u003ctable\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd colspan\u003d\"2\" class\u003d\"statText\"\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003chr\u003e\u003cp\u003eThis problem statement is the exclusive and proprietary property of TopCoder, Inc. Any unauthorized use or reproduction of this information without the prior written consent of TopCoder, Inc. is strictly prohibited. (c)2024, TopCoder, Inc. All rights reserved. \u003c/p\u003e\n \n "}}]}