problem_0500.py

"""Given a List of words, return the words that can be typed using letters of alphabet
on only one row's of American keyboard like the image below.
"""


class Solution:
    def __init__(self):
        self.lines = [
            {"e", "u", "y", "o", "r", "t", "w", "q", "p", "i"},
            {"g", "d", "s", "k", "f", "l", "a", "j", "h"},
            {"z", "m", "c", "b", "x", "n", "v"},
        ]

    def findWords(self, words):
        res = []
        for word in words:
            is_valid = True
            this_line = None
            for ch in word:
                for i in range(3):
                    if ch in self.lines[i]:
                        if this_line is not None:
                            if this_line != i:
                                is_valid = False
                                break
                        this_line = i
                        continue
            if is_valid:
                res.append(word)
        return res