LeetCode 1119. Remove Vowels from a String--C++，Java，Python解法

题目地址：1119. Remove Vowels from a String

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Given a string S, remove the vowels ‘a’, ‘e’, ‘i’, ‘o’, and ‘u’ from it, and return the new string.

Example 1:

Input: "leetcodeisacommunityforcoders"
Output: "ltcdscmmntyfrcdrs"

Example 2:

Input: "aeiou"
Output: ""

Note:

• S consists of lowercase English letters only.
• 1 <= S.length <= 1000

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这道题目是easy难度的，题目也容易理解，做起来也快。
Python第一版解决如下：

class Solution:
    def removeVowels(self, S: str) -> str:
        return S.replace("a","").replace("e","").replace("i","").replace("o","").replace("u","")

只超过了20%的人，改进后的做法如下：

class Solution:
    def removeVowels(self, S: str) -> str:
        res=''
        a={'a','e','i','o','u'}
        for i in S:
            if i not in a:
                res+=i
        return res

现在就超过了90%的人，我想不到更快的解法了。

Java解法如下：

class Solution {
    public String removeVowels(String S) {
        return S.replaceAll("[aeiou]", "");
    }
}

C++解法如下：

class Solution {
public:
    string removeVowels(string S) {
        set<char> vowels = {'a', 'e', 'i', 'o', 'u'};
        string result = "";
        for (int i = 0; i < S.size(); i++) {
            if (vowels.find(S[i]) != vowels.end()) {
                continue;
            } else {
                result += S[i];
            }
        }
        return result;
    }
};