Redact Document Phrases with Simultaneous Replacement

A document contains words or phrases that must be replaced using a supplied mapping. Perform all replacements against the original document so text inserted by one replacement is not processed again.

Implement redact_document(text: string, phrases: string[], replacements: string[]) -> string. The two arrays have equal length; phrases[i] maps to replacements[i].

Constraints & Assumptions

• Matching is case-sensitive and literal, including internal spaces.
• For this practice version, a match must have whole-word boundaries. Word characters are ASCII letters, digits, and underscore; the characters immediately before and after a match, if present, must not be word characters.
• Phrases are distinct, nonempty, and begin and end with a word character. Replacement strings may be empty and are inserted verbatim.
• Scan the original text left to right. At each position with one or more valid matches, choose the longest phrase, emit its replacement, and continue after the matched original span. Distinct phrases of equal length cannot both exactly match the same span.
• If no phrase matches at a position, preserve the original character.
• Boundary, overlap-priority, and simultaneous-replacement rules are explicit practice choices; the source gives the replacement-map task but does not specify these edge cases.
• All text is ASCII. Text length is at most 10,000, there are at most 100 phrases, and each phrase and replacement has at most 100 characters.

Examples

text = "Person One emailed Person."
phrases = ["Person","Person One"]
replacements = ["word","name"]
result = "name emailed word."

text = "red redwood blue"
phrases = ["red","blue"]
replacements = ["blue",""]
result = "blue redwood "

The inserted blue is not redacted again, and red does not match inside redwood.