Solution: Verifying an Alien Dictionary

Understand the process of verifying lexicographical order in an alien language by applying topological sort principles. This lesson shows how to efficiently compare adjacent words using a character order map, handle edge cases like prefixes, and optimize verification to confirm whether the given word list respects the alien dictionary order.

We'll cover the following...

Statement
Solution
- Naive approach
- Optimized approach using topological sort

Statement

In an alien language, the alphabet consists of the same lowercase English letters but arranged in a different order.

Given a list of words, words, written in this alien language, and a string order representing the order of the alien alphabet (as a permutation of lowercase letters), return TRUE if the words are sorted lexicographically according to order; otherwise, return FALSE.

Note: A word a is considered lexicographically smaller than word b if:
At the first position where the two words differ, the character in a comes before the character in b in the given order string.
If one word is a prefix of the other (and all compared characters are the same), then the shorter word is considered smaller.