<p>Given a string <code>s</code>, reverse only all the vowels in the string and return it.</p>

<p>The vowels are <code>&#39;a&#39;</code>, <code>&#39;e&#39;</code>, <code>&#39;i&#39;</code>, <code>&#39;o&#39;</code>, and <code>&#39;u&#39;</code>, and they can appear in both lower and upper cases, more than once.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<div class="example-block">
<p><strong>Input:</strong> <span class="example-io">s = &quot;IceCreAm&quot;</span></p>

<p><strong>Output:</strong> <span class="example-io">&quot;AceCreIm&quot;</span></p>

<p><strong>Explanation:</strong></p>

<p>The vowels in <code>s</code> are <code>[&#39;I&#39;, &#39;e&#39;, &#39;e&#39;, &#39;A&#39;]</code>. On reversing the vowels, s becomes <code>&quot;AceCreIm&quot;</code>.</p>
</div>

<p><strong class="example">Example 2:</strong></p>

<div class="example-block">
<p><strong>Input:</strong> <span class="example-io">s = &quot;leetcode&quot;</span></p>

<p><strong>Output:</strong> <span class="example-io">&quot;leotcede&quot;</span></p>
</div>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= s.length &lt;= 3 * 10<sup>5</sup></code></li>
	<li><code>s</code> consist of <strong>printable ASCII</strong> characters.</li>
</ul>

class Solution {
public:
    bool isVowel(char c) {
    c = tolower(c);
    if (c == 'a' || c == 'e' || c == 'i' || c == 'o' || c == 'u') {
        return true;
    }
    return false;
    }
    string reverseVowels(string s) {
        int x = 0 , y = s.length() - 1;

        while (x < y) {
            while (x < y && !isVowel(s[x])) {
                ++ x;
            }
            while (x < y && !isVowel(s[y])) {
                -- y;
            }

            swap(s[x], s[y]);
            ++ x , -- y;
        }
        return s;
    }
};
9200