Maximum Nesting Depth of the Parentheses
<p>Given a <strong>valid parentheses string</strong> <code>s</code>, return the <strong>nesting depth</strong> of<em> </em><code>s</code>. The nesting depth is the <strong>maximum</strong> number of nested parentheses.</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;(1+(2*3)+((8)/4))+1&quot;</span></p>

<p><strong>Output:</strong> <span class="example-io">3</span></p>

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

<p>Digit 8 is inside of 3 nested parentheses in the string.</p>
</div>

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

<div class="example-block">
<p><strong>Input:</strong> <span class="example-io">s = &quot;(1)+((2))+(((3)))&quot;</span></p>

<p><strong>Output:</strong> <span class="example-io">3</span></p>

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

<p>Digit 3 is inside of 3 nested parentheses in the string.</p>
</div>

<p><strong class="example">Example 3:</strong></p>

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

<p><strong>Output:</strong> <span class="example-io">3</span></p>
</div>

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

<ul>
	<li><code>1 &lt;= s.length &lt;= 100</code></li>
	<li><code>s</code> consists of digits <code>0-9</code> and characters <code>&#39;+&#39;</code>, <code>&#39;-&#39;</code>, <code>&#39;*&#39;</code>, <code>&#39;/&#39;</code>, <code>&#39;(&#39;</code>, and <code>&#39;)&#39;</code>.</li>
	<li>It is guaranteed that parentheses expression <code>s</code> is a VPS.</li>
</ul>
Stack; String
/**
 * @param {string} s
 * @return {number}
 */
var maxDepth = function (s) {
    let ans = 0;
    let d = 0;
    for (const c of s) {
        if (c === '(') {
            ans = Math.max(ans, ++d);
        } else if (c === ')') {
            --d;
        }
    }
    return ans;
};
