[Leetcode]819. Most Common Word

📄 Description

Example 1:

Input: paragraph = "Bob hit a ball, the hit BALL flew far after it was hit.", banned = ["hit"]
Output: "ball"
Explanation: 
"hit" occurs 3 times, but it is a banned word.
"ball" occurs twice (and no other word does), so it is the most frequent non-banned word in the paragraph. 
Note that words in the paragraph are not case sensitive,
that punctuation is ignored (even if adjacent to words, such as "ball,"), 
and that "hit" isn't the answer even though it occurs more because it is banned.

Example 2:

Input: paragraph = "a.", banned = []
Output: "a"

Constraints:

💻 My submission

class Solution:
    def mostCommonWord(self, paragraph: str, banned: List[str]) -> str:
        
        words=[x for x in re.sub('[^\w]', ' ', paragraph).lower().split() if x not in banned]
        
        counter=Counter(words)
        
        return counter.most_common(1)[0][0]

🔨 How to solve the problm

1.正規表現による入力値の前処理

2.Counterオブジェクトを利用してmost common(1)で回答する