922. Sort Array By Parity II

Given an array A of non-negative integers, half of the integers in A are odd, and half of the integers are even.

Sort the array so that whenever A[i] is odd, i is odd; and whenever A[i] is even, i is even.

You may return any answer array that satisfies this condition.

Example 1:

Input: [4,2,5,7]
Output: [4,5,2,7]
Explanation: [4,7,2,5], [2,5,4,7], [2,7,4,5] would also have been accepted.

Note:

1. 2 <= A.length <= 20000

2. A.length % 2 == 0

3. 0 <= A[i] <= 1000

# @param {Integer[]} a
# @return {Integer[]}
def sort_array_by_parity_ii(a)
  odd = []
  even = []
  output = []
  
  a.each do |k|
    odd << k if k.odd?
    even << k if k.even?
  end
  
  odd.length.times do
    output << even.pop
    output << odd.pop
  end  
  
  output
  
end