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 lexicographically 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).
Constraints:
-
1 <= words.length <= 100
-
1 <= words[i].length <= 20
-
order.length == 26
- All characters in
words[i]
andorder
are English lowercase letters.
SOLUTION:
class Solution:
def isSorted(self, nums):
n = len(nums)
for i in range(n - 1):
if nums[i] > nums[i + 1]:
return False
return True
def isAlienSorted(self, words: List[str], order: str) -> bool:
pos = {}
for i, c in enumerate(order):
pos[c] = i
return self.isSorted([tuple([pos.get(c, 0) for c in word]) for word in words])
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