Find Dictionary Words Represented by Repeated Letters

Find all dictionary words that could produce a supplied string by repeating characters in place. For example, help can produce heellp by repeating e and l.

Implement matching_repeated_words(text: string, dictionary: string[]) -> string[].

Constraints & Assumptions

The report describes ignoring repeated letters without a precise stretching rule. This practice contract permits each original character occurrence to repeat one or more times, with no minimum stretch length. It never deletes, reorders, or changes a character.

• Text and words contain lowercase ASCII letters. Empty strings are allowed.
• Dictionary entries are unique and total dictionary length is at most 1000000; text length is at most 100000. Return matching words in dictionary input order.
• Consecutive equal characters form a run. A word matches exactly when it has the same run characters in the same order as text and each word-run length is at most the corresponding text-run length.
• Repeated letters already present in a dictionary word remain meaningful: hellp can match heellp, but heeellp cannot, because its e-run is longer than the supplied string's.
• The empty word matches only empty text.

Example

text = "heellp"
dictionary = ["help","hellp","heelp","heeellp","heap"]
result = ["help","hellp","heelp"]

Explain why simply comparing sets of letters loses order and why collapsing runs without checking their lengths accepts words that could not expand to the input. Give time and memory complexity for comparing many dictionary entries.