g1001_1100.s1032_stream_of_characters.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 <code>words</code>. 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>. Implement the <code>StreamChecker</code> class: <ul> <li><code>StreamChecker(String[] words)</code> Initializes the object with the strings array <code>words</code>.</li> <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> </ul> Example 1: Input [“StreamChecker”, “query”, “query”, “query”, “query”, “query”, “query”, “query”, “query”, “query”, “query”, “query”, “query”] [<a href=""cd",-"f",-"kl"">"cd", "f", "kl"</a>, [“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: <pre><code> 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 </code></pre> Constraints: <ul> <li><code>1 <= words.length <= 2000</code></li> <li><code>1 <= words[i].length <= 2000</code></li> <li><code>words[i]</code> consists of lowercase English letters.</li> <li><code>letter</code> is a lowercase English letter.</li> <li>At most <code>4 * 104</code> calls will be made to query.</li> </ul>

Constructor Summary

Constructors

Constructor

Description

StreamChecker(String[] words)
Method Summary

Modifier and Type

Method

Description

void

insert(String s)

boolean

query(char letter)

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details
- StreamChecker
  
  public StreamChecker(String[] words)
Method Details
- insert
  
  public void insert(String s)
- query
  
  public boolean query(char letter)

Class StreamChecker

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Details

StreamChecker

Method Details

insert

query