input: Write a python function to determine the minimum number of modifications required to transform an integer array into a palindromic array. A palindromic array reads the same forwards and backwards. Each change allows you to convert one element to any other element.
  assert num_changes_to_palindrome([1,2,3,5,4,7,9,6]) == 4
  assert num_changes_to_palindrome([1, 2, 3, 4, 3, 2, 2]) == 1
  assert num_changes_to_palindrome([1, 4, 2]) == 1
  assert num_changes_to_palindrome([1, 4, 4, 2]) == 1
  assert num_changes_to_palindrome([1, 2, 3, 2, 1]) == 0
  assert num_changes_to_palindrome([3, 1, 1, 3]) == 0
  assert num_changes_to_palindrome([1]) == 0
  assert num_changes_to_palindrome([0, 1]) == 1
output: def num_changes_to_palindrome(arr):
      n = len(arr)
      changes = 0
      for i in range(n // 2):
          if arr[i] != arr[n - i - 1]:
              changes += 1
      return changes