Day 10 - LeetCode 345. Reverse Vowels of a String

LeetCode 345. Reverse Vowels of a String

題目

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".
Note: The vowels does not include the letter "y".

翻譯

給一個英文字串，將裡面的母音字母反轉。
範例1:
Given s = "hello", return "holle".
範例2：
Given s = "leetcode", return "leotcede".
注意： y不算在母音字母中。

想法

1.建立搜尋到母音的陣列
2.再次重新搜索, 然後跟母音陣列的字母互換

http://www.gotoabc.url.tw/kk/kklesson/kklesson1.htm
1. 英文有 26 個字母，其中 a e i o u 是字母的母音，其他是子音

正規化表示法
http://syunguo.blogspot.tw/2013/04/jsregular-expressions.html

詳細參閱

https://skyyen999.gitbooks.io/-leetcode-with-javascript/content/questions/345md.html

https://discuss.leetcode.com/topic/48150/my-4ms-solution-in-java-beats-98-20#

---

Code

/**
 * @param {string} s
 * @return {string}
 */
var reverseVowels = function(s) {

    if (s.length < 2) {
        return s;
    }
    //儲存找到的母音
    var vowels = [];

    for (let get_vowels of s) {
        //正規化搜尋, test() 方法用於檢測一個字符串是否匹配某個模式.
        if ( (/^[aeiou]$/i).test(get_vowels) ) {
            //儲存找到的母音, 加入陣列
            vowels.push(get_vowels);
        }
    }

    //轉換輸入字串為陣列
    var input_s_array = s.split('');
    //vowels 最大key值
    var vowels_max_key = vowels.length-1;

    for (let i =0; i < input_s_array.length; i++) {
        if ( (/^[aeiou]$/i).test(input_s_array[i]) ) {
            //互換母音
            input_s_array[i] = vowels[vowels_max_key--];
        }
    }

    return input_s_array.join('');
};

reverseVowels('leetcode');

Run

Your input
"hello"
"leetcode"

Your answer
"holle"
"leotcede"

Expected answer
"holle"
"leotcede"

Runtime: 112 ms