Maximum Value of an Ordered Triplet II
<p>You are given a <strong>0-indexed</strong> integer array <code>nums</code>.</p>

<p>Return <em><strong>the maximum value over all triplets of indices</strong></em> <code>(i, j, k)</code> <em>such that</em> <code>i &lt; j &lt; k</code><em>. </em>If all such triplets have a negative value, return <code>0</code>.</p>

<p>The <strong>value of a triplet of indices</strong> <code>(i, j, k)</code> is equal to <code>(nums[i] - nums[j]) * nums[k]</code>.</p>

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

<pre>
<strong>Input:</strong> nums = [12,6,1,2,7]
<strong>Output:</strong> 77
<strong>Explanation:</strong> The value of the triplet (0, 2, 4) is (nums[0] - nums[2]) * nums[4] = 77.
It can be shown that there are no ordered triplets of indices with a value greater than 77. 
</pre>

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

<pre>
<strong>Input:</strong> nums = [1,10,3,4,19]
<strong>Output:</strong> 133
<strong>Explanation:</strong> The value of the triplet (1, 2, 4) is (nums[1] - nums[2]) * nums[4] = 133.
It can be shown that there are no ordered triplets of indices with a value greater than 133.
</pre>

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

<pre>
<strong>Input:</strong> nums = [1,2,3]
<strong>Output:</strong> 0
<strong>Explanation:</strong> The only ordered triplet of indices (0, 1, 2) has a negative value of (nums[0] - nums[1]) * nums[2] = -3. Hence, the answer would be 0.
</pre>

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

<ul>
	<li><code>3 &lt;= nums.length &lt;= 10<sup>5</sup></code></li>
	<li><code>1 &lt;= nums[i] &lt;= 10<sup>6</sup></code></li>
</ul>
Array
function maximumTripletValue(nums: number[]): number {
    let [ans, mx, mxDiff] = [0, 0, 0];
    for (const x of nums) {
        ans = Math.max(ans, mxDiff * x);
        mxDiff = Math.max(mxDiff, mx - x);
        mx = Math.max(mx, x);
    }
    return ans;
}
