Find Words That Can Be Formed by Characters
<p>You are given an array of strings <code>words</code> and a string <code>chars</code>.</p>

<p>A string is <strong>good</strong> if it can be formed by characters from <code>chars</code> (each character can only be used once for <strong>each</strong> word in <code>words</code>).</p>

<p>Return <em>the sum of lengths of all good strings in words</em>.</p>

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

<pre>
<strong>Input:</strong> words = [&quot;cat&quot;,&quot;bt&quot;,&quot;hat&quot;,&quot;tree&quot;], chars = &quot;atach&quot;
<strong>Output:</strong> 6
<strong>Explanation:</strong> The strings that can be formed are &quot;cat&quot; and &quot;hat&quot; so the answer is 3 + 3 = 6.
</pre>

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

<pre>
<strong>Input:</strong> words = [&quot;hello&quot;,&quot;world&quot;,&quot;leetcode&quot;], chars = &quot;welldonehoneyr&quot;
<strong>Output:</strong> 10
<strong>Explanation:</strong> The strings that can be formed are &quot;hello&quot; and &quot;world&quot; so the answer is 5 + 5 = 10.
</pre>

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

<ul>
	<li><code>1 &lt;= words.length &lt;= 1000</code></li>
	<li><code>1 &lt;= words[i].length, chars.length &lt;= 100</code></li>
	<li><code>words[i]</code> and <code>chars</code> consist of lowercase English letters.</li>
</ul>
Array; Hash Table; String; Counting
class Solution {
    /**
     * @param String[] $words
     * @param String $chars
     * @return Integer
     */
    function countCharacters($words, $chars) {
        $sum = 0;
        for ($i = 0; $i < strlen($chars); $i++) {
            $hashtable[$chars[$i]] += 1;
        }
        for ($j = 0; $j < count($words); $j++) {
            $tmp = $hashtable;
            $sum += strlen($words[$j]);
            for ($k = 0; $k < strlen($words[$j]); $k++) {
                if (!isset($tmp[$words[$j][$k]]) || $tmp[$words[$j][$k]] === 0) {
                    $sum -= strlen($words[$j]);
                    break;
                }
                $tmp[$words[$j][$k]] -= 1;
            }
        }
        return $sum;
    }
}
