Largest Divisible Subset
<p>Given a set of <strong>distinct</strong> positive integers <code>nums</code>, return the largest subset <code>answer</code> such that every pair <code>(answer[i], answer[j])</code> of elements in this subset satisfies:</p>

<ul>
	<li><code>answer[i] % answer[j] == 0</code>, or</li>
	<li><code>answer[j] % answer[i] == 0</code></li>
</ul>

<p>If there are multiple solutions, return any of them.</p>

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

<pre>
<strong>Input:</strong> nums = [1,2,3]
<strong>Output:</strong> [1,2]
<strong>Explanation:</strong> [1,3] is also accepted.
</pre>

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

<pre>
<strong>Input:</strong> nums = [1,2,4,8]
<strong>Output:</strong> [1,2,4,8]
</pre>

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

<ul>
	<li><code>1 &lt;= nums.length &lt;= 1000</code></li>
	<li><code>1 &lt;= nums[i] &lt;= 2 * 10<sup>9</sup></code></li>
	<li>All the integers in <code>nums</code> are <strong>unique</strong>.</li>
</ul>
Array; Math; Dynamic Programming; Sorting
func largestDivisibleSubset(nums []int) (ans []int) {
	sort.Ints(nums)
	n := len(nums)
	f := make([]int, n)
	k := 0
	for i := 0; i < n; i++ {
		f[i] = 1
		for j := 0; j < i; j++ {
			if nums[i]%nums[j] == 0 {
				f[i] = max(f[i], f[j]+1)
			}
		}
		if f[k] < f[i] {
			k = i
		}
	}
	m := f[k]
	for i := k; m > 0; i-- {
		if nums[k]%nums[i] == 0 && f[i] == m {
			ans = append(ans, nums[i])
			k = i
			m--
		}
	}
	return
}