Class Solution
java.lang.Object
g2101_2200.s2122_recover_the_original_array.Solution
2122 - Recover the Original Array.<p>Hard</p>
<p>Alice had a <strong>0-indexed</strong> array <code>arr</code> consisting of <code>n</code> <strong>positive</strong> integers. She chose an arbitrary <strong>positive integer</strong> <code>k</code> and created two new <strong>0-indexed</strong> integer arrays <code>lower</code> and <code>higher</code> in the following manner:</p>
<ol>
<li><code>lower[i] = arr[i] - k</code>, for every index <code>i</code> where <code>0 <= i < n</code></li>
<li><code>higher[i] = arr[i] + k</code>, for every index <code>i</code> where <code>0 <= i < n</code></li>
</ol>
<p>Unfortunately, Alice lost all three arrays. However, she remembers the integers that were present in the arrays <code>lower</code> and <code>higher</code>, but not the array each integer belonged to. Help Alice and recover the original array.</p>
<p>Given an array <code>nums</code> consisting of <code>2n</code> integers, where <strong>exactly</strong> <code>n</code> of the integers were present in <code>lower</code> and the remaining in <code>higher</code>, return <em>the <strong>original</strong> array</em> <code>arr</code>. In case the answer is not unique, return <em><strong>any</strong> valid array</em>.</p>
<p><strong>Note:</strong> The test cases are generated such that there exists <strong>at least one</strong> valid array <code>arr</code>.</p>
<p><strong>Example 1:</strong></p>
<p><strong>Input:</strong> nums = [2,10,6,4,8,12]</p>
<p><strong>Output:</strong> [3,7,11]</p>
<p><strong>Explanation:</strong></p>
<p>If arr = [3,7,11] and k = 1, we get lower = [2,6,10] and higher = [4,8,12].</p>
<p>Combining lower and higher gives us [2,6,10,4,8,12], which is a permutation of nums.</p>
<p>Another valid possibility is that arr = [5,7,9] and k = 3. In that case, lower = [2,4,6] and higher = [8,10,12].</p>
<p><strong>Example 2:</strong></p>
<p><strong>Input:</strong> nums = [1,1,3,3]</p>
<p><strong>Output:</strong> [2,2]</p>
<p><strong>Explanation:</strong></p>
<p>If arr = [2,2] and k = 1, we get lower = [1,1] and higher = [3,3].</p>
<p>Combining lower and higher gives us [1,1,3,3], which is equal to nums.</p>
<p>Note that arr cannot be [1,3] because in that case, the only possible way to obtain [1,1,3,3] is with k = 0.</p>
<p>This is invalid since k must be positive.</p>
<p><strong>Example 3:</strong></p>
<p><strong>Input:</strong> nums = [5,435]</p>
<p><strong>Output:</strong> [220]</p>
<p><strong>Explanation:</strong> The only possible combination is arr = [220] and k = 215. Using them, we get lower = [5] and higher = [435].</p>
<p><strong>Constraints:</strong></p>
<ul>
<li><code>2 * n == nums.length</code></li>
<li><code>1 <= n <= 1000</code></li>
<li><code>1 <= nums[i] <= 10<sup>9</sup></code></li>
<li>The test cases are generated such that there exists <strong>at least one</strong> valid array <code>arr</code>.</li>
</ul>
-
Constructor Summary
Constructors -
Method Summary
-
Constructor Details
-
Solution
public Solution()
-
-
Method Details
-
recoverArray
public int[] recoverArray(int[] nums)
-