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Problem: Verifying an Alien Dictionary

Medium
30 min
Understand how to verify if words follow a specified alien dictionary order by applying lexicographical comparison rules. Explore the use of topological sort to assess character ordering and master checking if a given list of words is sorted according to an alien alphabet permutation.

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.

Constraints:

  • 11 \leq words.length 103\leq 10^3
  • 11 \leq words[i].length 20\leq 20
  • order.length ==26== 26
  • All the characters in words[i] and order are lowercase English letters.
Problem
Ask
Submissions

Problem: Verifying an Alien Dictionary

Medium
30 min
Understand how to verify if words follow a specified alien dictionary order by applying lexicographical comparison rules. Explore the use of topological sort to assess character ordering and master checking if a given list of words is sorted according to an alien alphabet permutation.

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.

Constraints:

  • 11 \leq words.length 103\leq 10^3
  • 11 \leq words[i].length 20\leq 20
  • order.length ==26== 26
  • All the characters in words[i] and order are lowercase English letters.