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48 lines
2.9 KiB
HTML
48 lines
2.9 KiB
HTML
<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>
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<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>
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<p>Implement the <code>StreamChecker</code> class:</p>
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<ul>
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<li><code>StreamChecker(String[] words)</code> Initializes the object with the strings array <code>words</code>.</li>
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<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>
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</ul>
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<p> </p>
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<p><strong>Example 1:</strong></p>
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<pre>
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<strong>Input</strong>
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["StreamChecker", "query", "query", "query", "query", "query", "query", "query", "query", "query", "query", "query", "query"]
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[[["cd", "f", "kl"]], ["a"], ["b"], ["c"], ["d"], ["e"], ["f"], ["g"], ["h"], ["i"], ["j"], ["k"], ["l"]]
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<strong>Output</strong>
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[null, false, false, false, true, false, true, false, false, false, false, false, true]
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<strong>Explanation</strong>
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StreamChecker streamChecker = new StreamChecker(["cd", "f", "kl"]);
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streamChecker.query("a"); // return False
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streamChecker.query("b"); // return False
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streamChecker.query("c"); // return False
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streamChecker.query("d"); // return True, because 'cd' is in the wordlist
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streamChecker.query("e"); // return False
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streamChecker.query("f"); // return True, because 'f' is in the wordlist
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streamChecker.query("g"); // return False
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streamChecker.query("h"); // return False
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streamChecker.query("i"); // return False
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streamChecker.query("j"); // return False
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streamChecker.query("k"); // return False
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streamChecker.query("l"); // return True, because 'kl' is in the wordlist
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</pre>
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<p> </p>
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<p><strong>Constraints:</strong></p>
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<ul>
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<li><code>1 <= words.length <= 2000</code></li>
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<li><code>1 <= words[i].length <= 2000</code></li>
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<li><code>words[i]</code> consists of lowercase English letters.</li>
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<li><code>letter</code> is a lowercase English letter.</li>
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<li>At most <code>4 * 10<sup>4</sup></code> calls will be made to query.</li>
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</ul>
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