Sort words by a custom alphabet

You are given a string order that lists characters from first to last in a custom alphabet. Each character appears in order at most once. You are also given a list of strings words.

Return words sorted by dictionary order under this alphabet:

• Compare two words from left to right. At the first position where they differ, the word whose character appears earlier in order comes first.
• If one word is a prefix of the other, the shorter word comes first.
• Equal words are both kept in the output.

Implement:

def custom_sort(order: str, words: list[str]) -> list[str]: ...

Constraints

• 1 <= len(order) <= 26, and every character in every word appears in order (ask your interviewer what to do if one does not).
• 0 <= len(words) <= 10^5, and 0 <= len(word) <= 100.

Example 1

order = "cba"
words = ["ab", "a", "c", "ba"]
output: ["c", "ba", "a", "ab"]

c ranks before b, which ranks before a. "a" is a prefix of "ab", so it comes first.

Example 2

order = "zyxwvutsrqponmlkjihgfedcba"
words = ["apple", "zoo", "banana"]
output: ["zoo", "banana", "apple"]

Reconstructed from the reported question; details may differ from what interviewers ask.