1935. Maximum Number of Words You Can Type | LeetCode

題目

https://leetcode.com/problems/maximum-number-of-words-you-can-type/description/?envType=daily-question&envId=2025-09-15

日期

2025/9/15

解法 1

1. 把字串根據空格分割成陣列
2. 用正規表達式判斷有沒有出現，沒有出現則可以 +1

class Solution {
    func canBeTypedWords(_ text: String, _ brokenLetters: String) -> Int {
        let group = text.split(separator: " ")
        guard !brokenLetters.isEmpty else { return group.count }
        guard let regex = try? Regex("[\(brokenLetters)]") else { return 0 }
        return group.reduce(into: 0) { result, string in
            result += string.contains(regex) ? 0 : 1
        }
    }
}

缺點

慢，看起來做了許多不必要的處理

解法 2

（檢討）

參考 iamhands0me 的解法後，發現可以不用用到正規表達式。寫法就可以更單純好懂。轉型成 Set 後還能用 isDisjoint 判定有沒有出現。

程式碼

class Solution {
    func canBeTypedWords(_ text: String, _ brokenLetters: String) -> Int {
        text
            .split(separator: " ")
            .count { [brokenSet = Set(brokenLetters)] word in
                brokenSet.isDisjoint(with: word)
            }
    }
}