16.20 T9键盘

解题思路

列表生成器形式的剪枝，缩小搜索空间

代码

class Solution:
    def getValidT9Words(self, num: str, words: List[str]) -> List[str]:
        kb = {'2':'abc', '3':'def', '4':'ghi', '5':'jkl', '6':'mno', '7':'pqrs', '8':'tuv', '9':'wxyz'}
        ns = list(num)
        candidate = words
        for i, n in enumerate(ns):
            candidate = [w for w in candidate if w[i] in kb[n]]

        return candidate