recover-the-original-array

Algorithms

Recover the Original Array

java

python

python3

mysql

mssql

oraclesql

csharp

javascript

typescript

bash

swift

kotlin

dart

golang

ruby

scala

html

pythonml

rust

racket

erlang

elixir

pythondata

react

vanillajs

postgresql

recoverArray

Alice had a 0-indexed array <code>arr</code> consisting of <code>n</code> positive integers. She chose an arbitrary positive integer <code>k</code> and created two new 0-indexed integer arrays <code>lower</code> and <code>higher</code> in the following manner:

<ol>
	<li><code>lower[i] = arr[i] - k</code>, for every index <code>i</code> where <code>0 &lt;= i &lt; n</code></li>
	<li><code>higher[i] = arr[i] + k</code>, for every index <code>i</code> where <code>0 &lt;= i &lt; n</code></li>
</ol>

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.

Given an array <code>nums</code> consisting of <code>2n</code> integers, where exactly <code>n</code> of the integers were present in <code>lower</code> and the remaining in <code>higher</code>, return the original array <code>arr</code>. In case the answer is not unique, return any valid array.

Note: The test cases are generated such that there exists at least one valid array <code>arr</code>.

&nbsp;
Example 1:

<pre>
Input: nums = [2,10,6,4,8,12]
Output: [3,7,11]
Explanation:
If arr = [3,7,11] and k = 1, we get lower = [2,6,10] and higher = [4,8,12].
Combining lower and higher gives us [2,6,10,4,8,12], which is a permutation of nums.
Another valid possibility is that arr = [5,7,9] and k = 3. In that case, lower = [2,4,6] and higher = [8,10,12]. 
</pre>

Example 2:

<pre>
Input: nums = [1,1,3,3]
Output: [2,2]
Explanation:
If arr = [2,2] and k = 1, we get lower = [1,1] and higher = [3,3].
Combining lower and higher gives us [1,1,3,3], which is equal to nums.
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.
This is invalid since k must be positive.
</pre>

Example 3:

<pre>
Input: nums = [5,435]
Output: [220]
Explanation:
The only possible combination is arr = [220] and k = 215. Using them, we get lower = [5] and higher = [435].
</pre>

&nbsp;
Constraints:

<ul>
	<li><code>2 * n == nums.length</code></li>
	<li><code>1 &lt;= n &lt;= 1000</code></li>
	<li><code>1 &lt;= nums[i] &lt;= 109</code></li>
	<li>The test cases are generated such that there exists at least one valid array <code>arr</code>.</li>
</ul>

Array

Hash Table

Sorting

Enumeration

1Kosmos

6sense

Accenture

Accolite

Acko

Activision

Addepar

Adobe

Aetion

Affinity

Affirm

Agoda

Airbnb

Airtel

Akamai

Akuna Capital

Alation

Alibaba

AllinCall

alphonso

Altimetrik

Amadeus

Amazon

Amdocs

American Express

Amobee

Analytics quotient

Ancestry

Anduril

Apna

AppDynamics

AppFolio

Apple

Apptio

AQR Capital Management LLC

Arcesium

Argo AI

Arista Networks

Aruba

Asana

Ascend

ASUS

AT&T

athenahealth

Atlassian

Audible

Aurora

Autodesk

Avalara

Avito

Axon

Baidu

Bank of America

Barclays

BitGo

BlackRock

BlackStone

Blend

Blizzard

Bloomberg

Bloomreach

BNY Mellon

Boeing

Bolt

Booking.com

BookMyShow

Bosch

Braze

Brex

Bridgewater Associates

Bungie

BuyHatke

ByteDance

C3 IoT

C3.ai

Cadence

Canonical

Capgemini

Capital One

Careem

carwale

Cashfree

Caterpillar

Cerner

Chargebee

Chewy

Chime

ciena

Cisco

Citadel

Citi

citibank

Citrix

Clari

ClearTax

Cleartrip

Online Assessment

Phone Interview

On Campus Interview

Onsite Interview

Don't know

last week

last month

last 3 months

last 6 months

more than 6 months

other