954. Array of Doubled Pairs ¶
Problem
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.
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 Explanation: 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 * 104
arr.length
is even.-105 <= arr[i] <= 105