Class StreamChecker


  • public class StreamChecker
    extends Object
    1032 - Stream of Characters\. Hard 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 `words`. For example, if `words = ["abc", "xyz"]` and the stream added the four characters (one by one) `'a'`, `'x'`, `'y'`, and `'z'`, your algorithm should detect that the suffix `"xyz"` of the characters `"axyz"` matches `"xyz"` from `words`. Implement the `StreamChecker` class: * `StreamChecker(String[] words)` Initializes the object with the strings array `words`. * `boolean query(char letter)` Accepts a new character from the stream and returns `true` if any non-empty suffix from the stream forms a word that is in `words`. **Example 1:** **Input** ["StreamChecker", "query", "query", "query", "query", "query", "query", "query", "query", "query", "query", "query", "query"] [[["cd", "f", "kl"]], ["a"], ["b"], ["c"], ["d"], ["e"], ["f"], ["g"], ["h"], ["i"], ["j"], ["k"], ["l"]] **Output:** [null, false, false, false, true, false, true, false, false, false, false, false, true] **Explanation:** StreamChecker streamChecker = new StreamChecker(["cd", "f", "kl"]); streamChecker.query("a"); // return False streamChecker.query("b"); // return False streamChecker.query("c"); // return False streamChecker.query("d"); // return True, because 'cd' is in the wordlist streamChecker.query("e"); // return False streamChecker.query("f"); // return True, because 'f' is in the wordlist streamChecker.query("g"); // return False streamChecker.query("h"); // return False streamChecker.query("i"); // return False streamChecker.query("j"); // return False streamChecker.query("k"); // return False streamChecker.query("l"); // return True, because 'kl' is in the wordlist **Constraints:** * `1 <= words.length <= 2000` * `1 <= words[i].length <= 2000` * `words[i]` consists of lowercase English letters. * `letter` is a lowercase English letter. * At most 4 * 104 calls will be made to query.
    • Constructor Detail

      • StreamChecker

        public StreamChecker​(String[] words)
    • Method Detail

      • insert

        public void insert​(String s)
      • query

        public boolean query​(char letter)