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Solution: Stream of Characters

Explore how to build a StreamChecker class that processes streams of characters and detects if any suffix matches words in a list. Understand how reversing words and using a Trie enables efficient suffix matching. Implement query methods to handle dynamic streams and optimize for time and space complexity through code walkthroughs.

Statement

Design a data structure that processes a stream of characters and, after each character is received, determines if a suffix of these characters is a string in a given array of strings words.

For example, if words = ["dog"] and the stream adds the characters ‘d’, ‘c’, ‘a’\text{`d', `c', `a'}, and ‘t’\text{`t'} in sequence, the algorithm should detect that the suffix "cat" of the stream "dcat" matches the word "cat" from the list.

So, for words, the goal is to detect if any of these words appear as a suffix of the stream built so far. To accomplish this, implement a class StreamChecker:

  • Constructor: Initializes the object with the list of target words.

  • boolean query(char letter): Appends a character to the stream and returns TRUE if any suffix of the stream matches a word in the list words.

Constraints:

  • 11\leq words.length ...