Array of Doubled Pairs

arrayhash tablegreedy

Problem Statement

Given an integer array of even length arr , return true if it is possible to reorder arr such that arr[2 i + 1] = 2 arr[2 * i] for every 0 <= i < len(arr) / 2 , or false otherwise .

Examples

Example 1

Input: arr = [3,1,3,6]
Output: false

Example 2

Input: arr = [2,1,2,6]
Output: false

Example 3

Input: arr = [4,-2,2,-4]
Output: true
We can take two groups, [-2,-4] and [2,4] to form [-2,-4,2,4] or [2,4,-2,-4].

Constraints

2 <= arr.length <= 3 * 10 ^4

arr.length is even.

-10 ^5 <= arr[i] <= 10 ^5

🤔

Medium

Difficulty

Topic Info

ModuleDSA

CategoryArray

Sub-topicHash Table