leetcode-problemset/leetcode/problem/shuffle-the-array.html

<p>Given the array <code>nums</code> consisting of <code>2n</code> elements in the form <code>[x<sub>1</sub>,x<sub>2</sub>,...,x<sub>n</sub>,y<sub>1</sub>,y<sub>2</sub>,...,y<sub>n</sub>]</code>.</p>

<p><em>Return the array in the form</em> <code>[x<sub>1</sub>,y<sub>1</sub>,x<sub>2</sub>,y<sub>2</sub>,...,x<sub>n</sub>,y<sub>n</sub>]</code>.</p>

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

<pre>
<strong>Input:</strong> nums = [2,5,1,3,4,7], n = 3
<strong>Output:</strong> [2,3,5,4,1,7] 
<strong>Explanation:</strong> Since x<sub>1</sub>=2, x<sub>2</sub>=5, x<sub>3</sub>=1, y<sub>1</sub>=3, y<sub>2</sub>=4, y<sub>3</sub>=7 then the answer is [2,3,5,4,1,7].
</pre>

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

<pre>
<strong>Input:</strong> nums = [1,2,3,4,4,3,2,1], n = 4
<strong>Output:</strong> [1,4,2,3,3,2,4,1]
</pre>

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

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

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

<ul>
	<li><code>1 &lt;= n &lt;= 500</code></li>
	<li><code>nums.length == 2n</code></li>
	<li><code>1 &lt;= nums[i] &lt;= 10^3</code></li>
</ul>