Problem

In an alien language, surprisingly they also use english lowercase letters, but possibly in a different order. The order of the alphabet is some permutation of lowercase letters.

Given a sequence of words written in the alien language, and the order of the alphabet, return true if and only if the given words are sorted lexicographicaly in this alien language.

Example 1:

Input: words = [“hello”,”leetcode”], order = “hlabcdefgijkmnopqrstuvwxyz”

Output: true

Explanation: As ‘h’ comes before ‘l’ in this language, then the sequence is sorted.

Example 2:

Input: words = [“word”,”world”,”row”], order = “worldabcefghijkmnpqstuvxyz”

Output: false

Explanation: As ‘d’ comes after ‘l’ in this language, then words[0] > words[1], hence the sequence is unsorted.

Example 3:

Input: words = [“apple”,”app”], order = “abcdefghijklmnopqrstuvwxyz”

Output: false

Explanation: The first three characters “app” match, and the second string is shorter (in size.) According to lexicographical rules “apple” > “app”, because ‘l’ > ‘∅’, where ‘∅’ is defined as the blank character which is less than any other character (More info).

Note:

1 <= words.length <= 100

1 <= words[i].length <= 20

order.length == 26

All characters in words[i] and order are english lowercase letters.

Pre analysis

Will transform it into human understood form (a-z) and then check for its correctness.

Another solution

var isAlienSorted = function(words, order) {
    for(let i = 0; i < words.length - 1; i++) {
        const maxWord = Math.max(words[i].length, words[i+1].length)
        for(let j = 0; j < maxWord; j++) {
            let wordA = order.indexOf(words[i][j]), wordB = order.indexOf(words[i+1][j])
            if(wordA > wordB) return false
            else if(wordB > wordA)break
        }
    }
    return true
};