https://www.codewars.com/kata/54da5a58ea159efa38000836/
Given an array of integers, find the one that appears an odd number of times.
There will always be only one integer that appears an odd number of times.
[7]
should return 7
, because it occurs 1 time (which is odd).
[0]
should return 0
, because it occurs 1 time (which is odd).
[1,1,2]
should return 2
, because it occurs 1 time (which is odd).
[0,1,0,1,0]
should return 0
, because it occurs 3 times (which is odd).
[1,2,2,3,3,3,4,3,3,3,2,2,1]
should return 4
, because it appears 1 time (which is odd).