count-the-number-of-consistent-strings_1684.py

# You are given a string allowed consisting of distinct characters and an array of strings words. A string is consistent if all characters in the string appear in the string allowed.

# Return the number of consistent strings in the array words.

# Example 1:

# Input: allowed = "ab", words = ["ad","bd","aaab","baa","badab"]
# Output: 2
# Explanation: Strings "aaab" and "baa" are consistent since they only contain characters 'a' and 'b'.
# Example 2:

# Input: allowed = "abc", words = ["a","b","c","ab","ac","bc","abc"]
# Output: 7
# Explanation: All strings are consistent.
# Example 3:

# Input: allowed = "cad", words = ["cc","acd","b","ba","bac","bad","ac","d"]
# Output: 4
# Explanation: Strings "cc", "acd", "ac", and "d" are consistent.

# ---------------------------------------Runtime 245 ms Beats 46.53% Memory 18.3 MB Beats 49.85%---------------------------------------

from typing import List


class Solution:
    def countConsistentStrings(self, allowed: str, words: List[str]) -> int:
        allowed_set = set(allowed)
        return len([x for x in words if not set(x) - allowed_set])