Solution: Verifying an Alien Dictionary

Explore how to determine if a list of words is sorted according to a custom alien alphabet. Learn to implement an efficient solution using topological sort principles by comparing adjacent words, understanding character order ranking, and handling edge cases. This lesson helps you grasp practical coding patterns for validating custom word orders with optimal time and space complexity.

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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.