mirror of
https://gitee.com/coder-xiaomo/leetcode-problemset
synced 2025-01-10 18:48:13 +08:00
41 lines
1.6 KiB
HTML
41 lines
1.6 KiB
HTML
<p>An integer array <code>original</code> is transformed into a <strong>doubled</strong> array <code>changed</code> by appending <strong>twice the value</strong> of every element in <code>original</code>, and then randomly <strong>shuffling</strong> the resulting array.</p>
|
|
|
|
<p>Given an array <code>changed</code>, return <code>original</code><em> if </em><code>changed</code><em> is a <strong>doubled</strong> array. If </em><code>changed</code><em> is not a <strong>doubled</strong> array, return an empty array. The elements in</em> <code>original</code> <em>may be returned in <strong>any</strong> order</em>.</p>
|
|
|
|
<p> </p>
|
|
<p><strong class="example">Example 1:</strong></p>
|
|
|
|
<pre>
|
|
<strong>Input:</strong> changed = [1,3,4,2,6,8]
|
|
<strong>Output:</strong> [1,3,4]
|
|
<strong>Explanation:</strong> One possible original array could be [1,3,4]:
|
|
- Twice the value of 1 is 1 * 2 = 2.
|
|
- Twice the value of 3 is 3 * 2 = 6.
|
|
- Twice the value of 4 is 4 * 2 = 8.
|
|
Other original arrays could be [4,3,1] or [3,1,4].
|
|
</pre>
|
|
|
|
<p><strong class="example">Example 2:</strong></p>
|
|
|
|
<pre>
|
|
<strong>Input:</strong> changed = [6,3,0,1]
|
|
<strong>Output:</strong> []
|
|
<strong>Explanation:</strong> changed is not a doubled array.
|
|
</pre>
|
|
|
|
<p><strong class="example">Example 3:</strong></p>
|
|
|
|
<pre>
|
|
<strong>Input:</strong> changed = [1]
|
|
<strong>Output:</strong> []
|
|
<strong>Explanation:</strong> changed is not a doubled array.
|
|
</pre>
|
|
|
|
<p> </p>
|
|
<p><strong>Constraints:</strong></p>
|
|
|
|
<ul>
|
|
<li><code>1 <= changed.length <= 10<sup>5</sup></code></li>
|
|
<li><code>0 <= changed[i] <= 10<sup>5</sup></code></li>
|
|
</ul>
|