[LeetCode][JavaScript][Python]Reverse Vowels of a String

Reverse Vowels of a String

Write a function that takes a string as input and reverse only the vowels of a string.

Example 1:
Given s = "hello", return "holle".

Example 2:
Given s = "leetcode", return "leotcede".

https://leetcode.com/problems/reverse-vowels-of-a-string/

 

 

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将字符串中的元音倒序排列，英语中元音为a, e, i, o, u，包含大小写。

双指针，一个在头一个在尾，找了元音就交换两个指针指向的内容。

最近在学python，之后会尽量用python。

 

Javascript:

/**
 * @param {string} s
 * @return {string}
 */
var reverseVowels = function(s) {
    var i, res = s.split(''), start = 0, end = s.length - 1,
    aVowels = ['a', 'e', 'i', 'o', 'u'];
    while(start < end){
        while(start < end && !isVowel(s[start]))
            start++;
        while(start < end && !isVowel(s[end]))
            end--;
        if(start !== end)
            swap(start, end);
        start++;
        end--;
    }
    return res.join('');
    
    function isVowel(char){
        if(aVowels.indexOf(char.toLowerCase()) !== -1){
            return true;
        }
        return false;
    }
    function swap(i, j){
        var temp = res[i];
        res[i] = res[j];
        res[j] = temp;
    }
};

 

Python:

class Solution(object):
    def reverseVowels(self, s):
        res = list(s)
        vowels = ['a', 'e', 'i', 'o', 'u']
        start = 0; end = len(s) - 1
        while start < end:
            while start < end and (s[start].lower() not in vowels):
                start += 1
            while start < end and (s[end].lower() not in vowels):       
                end -= 1
            if(start != end):
                tmp = res[start]
                res[start] = res[end]
                res[end] = tmp
            start += 1; end -= 1
        return ''.join(res)