HTMLify

class Solution:
    def findWords(self, words: List[str]) -> List[str]:
        rows = [
            "qwertyuiop",
            "asdfghjkl",
            "zxcvbnm",
        ]
        ans = []
        for word in words:
            row_used = set()
            for c in word.lower():
                for i, row in enumerate(rows):
                    if c in row:
                        row_used.add(i)
            if len(row_used) == 1:
                ans.append(word)
        return ans