Rotating the Box
<p>You are given an <code>m x n</code> matrix of characters <code>boxGrid</code> representing a side-view of a box. Each cell of the box is one of the following:</p>

<ul>
	<li>A stone <code>&#39;#&#39;</code></li>
	<li>A stationary obstacle <code>&#39;*&#39;</code></li>
	<li>Empty <code>&#39;.&#39;</code></li>
</ul>

<p>The box is rotated <strong>90 degrees clockwise</strong>, causing some of the stones to fall due to gravity. Each stone falls down until it lands on an obstacle, another stone, or the bottom of the box. Gravity <strong>does not</strong> affect the obstacles&#39; positions, and the inertia from the box&#39;s rotation <strong>does not </strong>affect the stones&#39; horizontal positions.</p>

<p>It is <strong>guaranteed</strong> that each stone in <code>boxGrid</code> rests on an obstacle, another stone, or the bottom of the box.</p>

<p>Return <em>an </em><code>n x m</code><em> matrix representing the box after the rotation described above</em>.</p>

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

<p><img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/1800-1899/1861.Rotating%20the%20Box/images/rotatingtheboxleetcodewithstones.png" style="width: 300px; height: 150px;" /></p>

<pre>
<strong>Input:</strong> boxGrid = [[&quot;#&quot;,&quot;.&quot;,&quot;#&quot;]]
<strong>Output:</strong> [[&quot;.&quot;],
&nbsp;        [&quot;#&quot;],
&nbsp;        [&quot;#&quot;]]
</pre>

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

<p><img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/1800-1899/1861.Rotating%20the%20Box/images/rotatingtheboxleetcode2withstones.png" style="width: 375px; height: 195px;" /></p>

<pre>
<strong>Input:</strong> boxGrid = [[&quot;#&quot;,&quot;.&quot;,&quot;*&quot;,&quot;.&quot;],
&nbsp;             [&quot;#&quot;,&quot;#&quot;,&quot;*&quot;,&quot;.&quot;]]
<strong>Output:</strong> [[&quot;#&quot;,&quot;.&quot;],
&nbsp;        [&quot;#&quot;,&quot;#&quot;],
&nbsp;        [&quot;*&quot;,&quot;*&quot;],
&nbsp;        [&quot;.&quot;,&quot;.&quot;]]
</pre>

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

<p><img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/1800-1899/1861.Rotating%20the%20Box/images/rotatingtheboxleetcode3withstone.png" style="width: 400px; height: 218px;" /></p>

<pre>
<strong>Input:</strong> boxGrid = [[&quot;#&quot;,&quot;#&quot;,&quot;*&quot;,&quot;.&quot;,&quot;*&quot;,&quot;.&quot;],
&nbsp;             [&quot;#&quot;,&quot;#&quot;,&quot;#&quot;,&quot;*&quot;,&quot;.&quot;,&quot;.&quot;],
&nbsp;             [&quot;#&quot;,&quot;#&quot;,&quot;#&quot;,&quot;.&quot;,&quot;#&quot;,&quot;.&quot;]]
<strong>Output:</strong> [[&quot;.&quot;,&quot;#&quot;,&quot;#&quot;],
&nbsp;        [&quot;.&quot;,&quot;#&quot;,&quot;#&quot;],
&nbsp;        [&quot;#&quot;,&quot;#&quot;,&quot;*&quot;],
&nbsp;        [&quot;#&quot;,&quot;*&quot;,&quot;.&quot;],
&nbsp;        [&quot;#&quot;,&quot;.&quot;,&quot;*&quot;],
&nbsp;        [&quot;#&quot;,&quot;.&quot;,&quot;.&quot;]]
</pre>

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

<ul>
	<li><code>m == boxGrid.length</code></li>
	<li><code>n == boxGrid[i].length</code></li>
	<li><code>1 &lt;= m, n &lt;= 500</code></li>
	<li><code>boxGrid[i][j]</code> is either <code>&#39;#&#39;</code>, <code>&#39;*&#39;</code>, or <code>&#39;.&#39;</code>.</li>
</ul>
Array; Two Pointers; Matrix
func rotateTheBox(box [][]byte) [][]byte {
	m, n := len(box), len(box[0])
	ans := make([][]byte, n)
	for i := range ans {
		ans[i] = make([]byte, m)
	}
	for i := 0; i < m; i++ {
		for j := 0; j < n; j++ {
			ans[j][m-i-1] = box[i][j]
		}
	}
	for j := 0; j < m; j++ {
		q := []int{}
		for i := n - 1; i >= 0; i-- {
			if ans[i][j] == '*' {
				q = []int{}
			} else if ans[i][j] == '.' {
				q = append(q, i)
			} else if len(q) > 0 {
				ans[q[0]][j] = '#'
				q = q[1:]
				ans[i][j] = '.'
				q = append(q, i)
			}
		}
	}
	return ans
}