How should I practice Classify an Alien Dictionary Ordering?

Start by reading the full statement, solve the visible examples, then compare the pattern against related ZipRecruiter phone screen and onsite interview problems in FastPrep.

Is Classify an Alien Dictionary Ordering associated with ZipRecruiter?

FastPrep tags this as a ZipRecruiter phone screen and onsite interview coding practice problem when the problem catalog has that company and stage context.

Classify an Alien Dictionary Ordering

ZipRecruiter● HardNEW GRADPHONE SCREENONSITE INTERVIEW

Learn

Problem statement

words is intended to be sorted under an unknown alphabet. Derive precedence edges from the first differing character of every adjacent pair and include every observed character.

Return the unique character order when exactly one topological ordering exists.
Return AMBIGUOUS when multiple orders are valid.
Return INVALID for a cycle or when a longer word precedes its exact prefix.

Function

alienDictionaryOrder(words: String[]) → String

Examples

Example 1

words = ["wdc","wdr","cd","dd","dr"]return = "wcdr"

The adjacent differences force the unique order wcdr.

Example 2

words = ["ab","ac"]return = "AMBIGUOUS"

Only b before c is fixed, leaving a unconstrained.

Constraints

0 <= words.length <= 10000
The total number of lowercase letters is at most 100000.