Largest Number At Least Twice of Others
<p>You are given an integer array <code>nums</code> where the largest integer is <strong>unique</strong>.</p>

<p>Determine whether the largest element in the array is <strong>at least twice</strong> as much as every other number in the array. If it is, return <em>the <strong>index</strong> of the largest element, or return </em><code>-1</code><em> otherwise</em>.</p>

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

<pre>
<strong>Input:</strong> nums = [3,6,1,0]
<strong>Output:</strong> 1
<strong>Explanation:</strong> 6 is the largest integer.
For every other number in the array x, 6 is at least twice as big as x.
The index of value 6 is 1, so we return 1.
</pre>

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

<pre>
<strong>Input:</strong> nums = [1,2,3,4]
<strong>Output:</strong> -1
<strong>Explanation:</strong> 4 is less than twice the value of 3, so we return -1.
</pre>

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

<ul>
	<li><code>2 &lt;= nums.length &lt;= 50</code></li>
	<li><code>0 &lt;= nums[i] &lt;= 100</code></li>
	<li>The largest element in <code>nums</code> is unique.</li>
</ul>
Array; Sorting
/**
 * @param {number[]} nums
 * @return {number}
 */
var dominantIndex = function (nums) {
    let k = 0;
    for (let i = 0; i < nums.length; ++i) {
        if (nums[i] > nums[k]) {
            k = i;
        }
    }
    for (let i = 0; i < nums.length; ++i) {
        if (i !== k && nums[k] < nums[i] * 2) {
            return -1;
        }
    }
    return k;
};
