java.lang.Object
g2001_2100.s2007_find_original_array_from_doubled_array.Solution

public class Solution extends Object
2007 - Find Original Array From Doubled Array.

Medium

An integer array original is transformed into a doubled array changed by appending twice the value of every element in original, and then randomly shuffling the resulting array.

Given an array changed, return original if changed is a doubled array. If changed is not a doubled array, return an empty array. The elements in original may be returned in any order.

Example 1:

Input: changed = [1,3,4,2,6,8]

Output: [1,3,4]

Explanation: 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].

Example 2:

Input: changed = [6,3,0,1]

Output: []

Explanation: changed is not a doubled array.

Example 3:

Input: changed = [1]

Output: []

Explanation: changed is not a doubled array.

Constraints:

  • 1 <= changed.length <= 105
  • 0 <= changed[i] <= 105
  • Constructor Details

    • Solution

      public Solution()
  • Method Details

    • findOriginalArray

      public int[] findOriginalArray(int[] changed)