Vowel Spellchecker
<p>Given a <code>wordlist</code>, we want to implement a spellchecker that converts a query word into a correct word.</p>

<p>For a given <code>query</code> word, the spell checker handles two categories of spelling mistakes:</p>

<ul>
	<li>Capitalization: If the query matches a word in the wordlist (<strong>case-insensitive</strong>), then the query word is returned with the same case as the case in the wordlist.

    <ul>
    	<li>Example: <code>wordlist = [&quot;yellow&quot;]</code>, <code>query = &quot;YellOw&quot;</code>: <code>correct = &quot;yellow&quot;</code></li>
    	<li>Example: <code>wordlist = [&quot;Yellow&quot;]</code>, <code>query = &quot;yellow&quot;</code>: <code>correct = &quot;Yellow&quot;</code></li>
    	<li>Example: <code>wordlist = [&quot;yellow&quot;]</code>, <code>query = &quot;yellow&quot;</code>: <code>correct = &quot;yellow&quot;</code></li>
    </ul>
    </li>
    <li>Vowel Errors: If after replacing the vowels <code>(&#39;a&#39;, &#39;e&#39;, &#39;i&#39;, &#39;o&#39;, &#39;u&#39;)</code> of the query word with any vowel individually, it matches a word in the wordlist (<strong>case-insensitive</strong>), then the query word is returned with the same case as the match in the wordlist.
    <ul>
    	<li>Example: <code>wordlist = [&quot;YellOw&quot;]</code>, <code>query = &quot;yollow&quot;</code>: <code>correct = &quot;YellOw&quot;</code></li>
    	<li>Example: <code>wordlist = [&quot;YellOw&quot;]</code>, <code>query = &quot;yeellow&quot;</code>: <code>correct = &quot;&quot;</code> (no match)</li>
    	<li>Example: <code>wordlist = [&quot;YellOw&quot;]</code>, <code>query = &quot;yllw&quot;</code>: <code>correct = &quot;&quot;</code> (no match)</li>
    </ul>
    </li>

</ul>

<p>In addition, the spell checker operates under the following precedence rules:</p>

<ul>
	<li>When the query exactly matches a word in the wordlist (<strong>case-sensitive</strong>), you should return the same word back.</li>
	<li>When the query matches a word up to capitlization, you should return the first such match in the wordlist.</li>
	<li>When the query matches a word up to vowel errors, you should return the first such match in the wordlist.</li>
	<li>If the query has no matches in the wordlist, you should return the empty string.</li>
</ul>

<p>Given some <code>queries</code>, return a list of words <code>answer</code>, where <code>answer[i]</code> is the correct word for <code>query = queries[i]</code>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
<pre><strong>Input:</strong> wordlist = ["KiTe","kite","hare","Hare"], queries = ["kite","Kite","KiTe","Hare","HARE","Hear","hear","keti","keet","keto"]
<strong>Output:</strong> ["kite","KiTe","KiTe","Hare","hare","","","KiTe","","KiTe"]
</pre><p><strong class="example">Example 2:</strong></p>
<pre><strong>Input:</strong> wordlist = ["yellow"], queries = ["YellOw"]
<strong>Output:</strong> ["yellow"]
</pre>
<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= wordlist.length, queries.length &lt;= 5000</code></li>
	<li><code>1 &lt;= wordlist[i].length, queries[i].length &lt;= 7</code></li>
	<li><code>wordlist[i]</code> and <code>queries[i]</code> consist only of only English letters.</li>
</ul>
Array; Hash Table; String
func spellchecker(wordlist []string, queries []string) (ans []string) {
	s := map[string]bool{}
	low := map[string]string{}
	pat := map[string]string{}
	f := func(w string) string {
		res := []byte(w)
		for i := range res {
			if res[i] == 'a' || res[i] == 'e' || res[i] == 'i' || res[i] == 'o' || res[i] == 'u' {
				res[i] = '*'
			}
		}
		return string(res)
	}
	for _, w := range wordlist {
		s[w] = true
		t := strings.ToLower(w)
		if _, ok := low[t]; !ok {
			low[t] = w
		}
		if _, ok := pat[f(t)]; !ok {
			pat[f(t)] = w
		}
	}
	for _, q := range queries {
		if s[q] {
			ans = append(ans, q)
			continue
		}
		q = strings.ToLower(q)
		if s, ok := low[q]; ok {
			ans = append(ans, s)
			continue
		}
		q = f(q)
		if s, ok := pat[q]; ok {
			ans = append(ans, s)
			continue
		}
		ans = append(ans, "")
	}
	return
}