Strictly Increasing or Decreasing

Create a function that takes an array and determines whether it's strictly increasing, strictly decreasing, or neither.

Examples

check([1, 2, 3]) ➞ "increasing"

check([3, 2, 1]) ➞ "decreasing"

check([1, 2, 1]) ➞ "neither"

check([1, 1, 2]) ➞ "neither"

Notes

• The last example does NOT count as strictly increasing, since 1-indexed 1 is not strictly greater than the 0-indexed 1.
• Input arrays have a minimum length of 2.