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"title": "Stream of Characters",
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"content": "<p>Design an algorithm that accepts a stream of characters and checks if a suffix of these characters is a string of a given array of strings <code>words</code>.</p>\n\n<p>For example, if <code>words = ["abc", "xyz"]</code> and the stream added the four characters (one by one) <code>'a'</code>, <code>'x'</code>, <code>'y'</code>, and <code>'z'</code>, your algorithm should detect that the suffix <code>"xyz"</code> of the characters <code>"axyz"</code> matches <code>"xyz"</code> from <code>words</code>.</p>\n\n<p>Implement the <code>StreamChecker</code> class:</p>\n\n<ul>\n\t<li><code>StreamChecker(String[] words)</code> Initializes the object with the strings array <code>words</code>.</li>\n\t<li><code>boolean query(char letter)</code> Accepts a new character from the stream and returns <code>true</code> if any non-empty suffix from the stream forms a word that is in <code>words</code>.</li>\n</ul>\n\n<p> </p>\n<p><strong>Example 1:</strong></p>\n\n<pre>\n<strong>Input</strong>\n["StreamChecker", "query", "query", "query", "query", "query", "query", "query", "query", "query", "query", "query", "query"]\n[[["cd", "f", "kl"]], ["a"], ["b"], ["c"], ["d"], ["e"], ["f"], ["g"], ["h"], ["i"], ["j"], ["k"], ["l"]]\n<strong>Output</strong>\n[null, false, false, false, true, false, true, false, false, false, false, false, true]\n\n<strong>Explanation</strong>\nStreamChecker streamChecker = new StreamChecker(["cd", "f", "kl"]);\nstreamChecker.query("a"); // return False\nstreamChecker.query("b"); // return False\nstreamChecker.query("c"); // return False\nstreamChecker.query("d"); // return True, because 'cd' is in the wordlist\nstreamChecker.query("e"); // return False\nstreamChecker.query("f"); // return True, because 'f' is in the wordlist\nstreamChecker.query("g"); // return False\nstreamChecker.query("h"); // return False\nstreamChecker.query("i"); // return False\nstreamChecker.query("j"); // return False\nstreamChecker.query("k"); // return False\nstreamChecker.query("l"); // return True, because 'kl' is in the wordlist\n</pre>\n\n<p> </p>\n<p><strong>Constraints:</strong></p>\n\n<ul>\n\t<li><code>1 <= words.length <= 2000</code></li>\n\t<li><code>1 <= words[i].length <= 2000</code></li>\n\t<li><code>words[i]</code> consists of lowercase English letters.</li>\n\t<li><code>letter</code> is a lowercase English letter.</li>\n\t<li>At most <code>4 * 10<sup>4</sup></code> calls will be made to query.</li>\n</ul>\n",
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"code": "class StreamChecker {\npublic:\n StreamChecker(vector<string>& words) {\n \n }\n \n bool query(char letter) {\n \n }\n};\n\n/**\n * Your StreamChecker object will be instantiated and called as such:\n * StreamChecker* obj = new StreamChecker(words);\n * bool param_1 = obj->query(letter);\n */",
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"code": "class StreamChecker {\n\n public StreamChecker(String[] words) {\n \n }\n \n public boolean query(char letter) {\n \n }\n}\n\n/**\n * Your StreamChecker object will be instantiated and called as such:\n * StreamChecker obj = new StreamChecker(words);\n * boolean param_1 = obj.query(letter);\n */",
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"lang": "Python",
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"code": "class StreamChecker(object):\n\n def __init__(self, words):\n \"\"\"\n :type words: List[str]\n \"\"\"\n \n\n def query(self, letter):\n \"\"\"\n :type letter: str\n :rtype: bool\n \"\"\"\n \n\n\n# Your StreamChecker object will be instantiated and called as such:\n# obj = StreamChecker(words)\n# param_1 = obj.query(letter)",
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"code": "class StreamChecker:\n\n def __init__(self, words: List[str]):\n \n\n def query(self, letter: str) -> bool:\n \n\n\n# Your StreamChecker object will be instantiated and called as such:\n# obj = StreamChecker(words)\n# param_1 = obj.query(letter)",
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"lang": "C",
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"code": "\n\n\ntypedef struct {\n \n} StreamChecker;\n\n\nStreamChecker* streamCheckerCreate(char ** words, int wordsSize) {\n \n}\n\nbool streamCheckerQuery(StreamChecker* obj, char letter) {\n \n}\n\nvoid streamCheckerFree(StreamChecker* obj) {\n \n}\n\n/**\n * Your StreamChecker struct will be instantiated and called as such:\n * StreamChecker* obj = streamCheckerCreate(words, wordsSize);\n * bool param_1 = streamCheckerQuery(obj, letter);\n \n * streamCheckerFree(obj);\n*/",
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"code": "public class StreamChecker {\n\n public StreamChecker(string[] words) {\n \n }\n \n public bool Query(char letter) {\n \n }\n}\n\n/**\n * Your StreamChecker object will be instantiated and called as such:\n * StreamChecker obj = new StreamChecker(words);\n * bool param_1 = obj.Query(letter);\n */",
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"lang": "JavaScript",
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"code": "/**\n * @param {string[]} words\n */\nvar StreamChecker = function(words) {\n \n};\n\n/** \n * @param {character} letter\n * @return {boolean}\n */\nStreamChecker.prototype.query = function(letter) {\n \n};\n\n/** \n * Your StreamChecker object will be instantiated and called as such:\n * var obj = new StreamChecker(words)\n * var param_1 = obj.query(letter)\n */",
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"lang": "Ruby",
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"code": "class StreamChecker\n\n=begin\n :type words: String[]\n=end\n def initialize(words)\n \n end\n\n\n=begin\n :type letter: Character\n :rtype: Boolean\n=end\n def query(letter)\n \n end\n\n\nend\n\n# Your StreamChecker object will be instantiated and called as such:\n# obj = StreamChecker.new(words)\n# param_1 = obj.query(letter)",
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"lang": "Swift",
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"code": "\nclass StreamChecker {\n\n init(_ words: [String]) {\n \n }\n \n func query(_ letter: Character) -> Bool {\n \n }\n}\n\n/**\n * Your StreamChecker object will be instantiated and called as such:\n * let obj = StreamChecker(words)\n * let ret_1: Bool = obj.query(letter)\n */",
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"lang": "Go",
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"code": "type StreamChecker struct {\n \n}\n\n\nfunc Constructor(words []string) StreamChecker {\n \n}\n\n\nfunc (this *StreamChecker) Query(letter byte) bool {\n \n}\n\n\n/**\n * Your StreamChecker object will be instantiated and called as such:\n * obj := Constructor(words);\n * param_1 := obj.Query(letter);\n */",
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"lang": "Scala",
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"code": "class StreamChecker(_words: Array[String]) {\n\n def query(letter: Char): Boolean = {\n \n }\n\n}\n\n/**\n * Your StreamChecker object will be instantiated and called as such:\n * var obj = new StreamChecker(words)\n * var param_1 = obj.query(letter)\n */",
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"lang": "Kotlin",
"langSlug": "kotlin",
"code": "class StreamChecker(words: Array<String>) {\n\n fun query(letter: Char): Boolean {\n \n }\n\n}\n\n/**\n * Your StreamChecker object will be instantiated and called as such:\n * var obj = StreamChecker(words)\n * var param_1 = obj.query(letter)\n */",
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"lang": "Rust",
"langSlug": "rust",
"code": "struct StreamChecker {\n\n}\n\n\n/** \n * `&self` means the method takes an immutable reference.\n * If you need a mutable reference, change it to `&mut self` instead.\n */\nimpl StreamChecker {\n\n fn new(words: Vec<String>) -> Self {\n \n }\n \n fn query(&self, letter: char) -> bool {\n \n }\n}\n\n/**\n * Your StreamChecker object will be instantiated and called as such:\n * let obj = StreamChecker::new(words);\n * let ret_1: bool = obj.query(letter);\n */",
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"lang": "PHP",
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"code": "class StreamChecker {\n /**\n * @param String[] $words\n */\n function __construct($words) {\n \n }\n \n /**\n * @param String $letter\n * @return Boolean\n */\n function query($letter) {\n \n }\n}\n\n/**\n * Your StreamChecker object will be instantiated and called as such:\n * $obj = StreamChecker($words);\n * $ret_1 = $obj->query($letter);\n */",
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"lang": "TypeScript",
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"code": "class StreamChecker {\n constructor(words: string[]) {\n\n }\n\n query(letter: string): boolean {\n\n }\n}\n\n/**\n * Your StreamChecker object will be instantiated and called as such:\n * var obj = new StreamChecker(words)\n * var param_1 = obj.query(letter)\n */",
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"lang": "Racket",
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"code": "(define stream-checker%\n (class object%\n (super-new)\n\n ; words : (listof string?)\n (init-field\n words)\n \n ; query : char? -> boolean?\n (define/public (query letter)\n\n )))\n\n;; Your stream-checker% object will be instantiated and called as such:\n;; (define obj (new stream-checker% [words words]))\n;; (define param_1 (send obj query letter))",
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"lang": "Erlang",
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"code": "-spec stream_checker_init_(Words :: [unicode:unicode_binary()]) -> any().\nstream_checker_init_(Words) ->\n .\n\n-spec stream_checker_query(Letter :: char()) -> boolean().\nstream_checker_query(Letter) ->\n .\n\n\n%% Your functions will be called as such:\n%% stream_checker_init_(Words),\n%% Param_1 = stream_checker_query(Letter),\n\n%% stream_checker_init_ will be called before every test case, in which you can do some necessary initializations.",
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"code": "defmodule StreamChecker do\n @spec init_(words :: [String.t]) :: any\n def init_(words) do\n\n end\n\n @spec query(letter :: char) :: boolean\n def query(letter) do\n\n end\nend\n\n# Your functions will be called as such:\n# StreamChecker.init_(words)\n# param_1 = StreamChecker.query(letter)\n\n# StreamChecker.init_ will be called before every test case, in which you can do some necessary initializations.",
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"sampleTestCase": "[\"StreamChecker\",\"query\",\"query\",\"query\",\"query\",\"query\",\"query\",\"query\",\"query\",\"query\",\"query\",\"query\",\"query\"]\n[[[\"cd\",\"f\",\"kl\"]],[\"a\"],[\"b\"],[\"c\"],[\"d\"],[\"e\"],[\"f\"],[\"g\"],[\"h\"],[\"i\"],[\"j\"],[\"k\"],[\"l\"]]",
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