Maximum Beauty of an Array After Applying Operation
<p>You are given a <strong>0-indexed</strong> array <code>nums</code> and a <strong>non-negative</strong> integer <code>k</code>.</p>

<p>In one operation, you can do the following:</p>

<ul>
	<li>Choose an index <code>i</code> that <strong>hasn&#39;t been chosen before</strong> from the range <code>[0, nums.length - 1]</code>.</li>
	<li>Replace <code>nums[i]</code> with any integer from the range <code>[nums[i] - k, nums[i] + k]</code>.</li>
</ul>

<p>The <strong>beauty</strong> of the array is the length of the longest subsequence consisting of equal elements.</p>

<p>Return <em>the <strong>maximum</strong> possible beauty of the array </em><code>nums</code><em> after applying the operation any number of times.</em></p>

<p><strong>Note</strong> that you can apply the operation to each index <strong>only once</strong>.</p>

<p>A&nbsp;<strong>subsequence</strong> of an array is a new array generated from the original array by deleting some elements (possibly none) without changing the order of the remaining elements.</p>

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

<pre>
<strong>Input:</strong> nums = [4,6,1,2], k = 2
<strong>Output:</strong> 3
<strong>Explanation:</strong> In this example, we apply the following operations:
- Choose index 1, replace it with 4 (from range [4,8]), nums = [4,4,1,2].
- Choose index 3, replace it with 4 (from range [0,4]), nums = [4,4,1,4].
After the applied operations, the beauty of the array nums is 3 (subsequence consisting of indices 0, 1, and 3).
It can be proven that 3 is the maximum possible length we can achieve.
</pre>

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

<pre>
<strong>Input:</strong> nums = [1,1,1,1], k = 10
<strong>Output:</strong> 4
<strong>Explanation:</strong> In this example we don&#39;t have to apply any operations.
The beauty of the array nums is 4 (whole array).
</pre>

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

<ul>
	<li><code>1 &lt;= nums.length &lt;= 10<sup>5</sup></code></li>
	<li><code>0 &lt;= nums[i], k &lt;= 10<sup>5</sup></code></li>
</ul>
Array; Binary Search; Sorting; Sliding Window
func maximumBeauty(nums []int, k int) (ans int) {
	m := slices.Max(nums)
	m += k*2 + 2
	d := make([]int, m)
	for _, x := range nums {
		d[x]++
		d[x+k*2+1]--
	}
	s := 0
	for _, x := range d {
		s += x
		if ans < s {
			ans = s
		}
	}
	return
}