0896-monotonic-array.rb

# frozen_string_literal: true

# 896. Monotonic Array
# Easy
# https://leetcode.com/problems/monotonic-array

=begin
An array is monotonic if it is either monotone increasing or monotone decreasing.
An array nums is monotone increasing if for all i <= j, nums[i] <= nums[j]. An array nums is monotone decreasing if for all i <= j, nums[i] >= nums[j].
Given an integer array nums, return true if the given array is monotonic, or false otherwise.

Example 1:
Input: nums = [1,2,2,3]
Output: true

Example 2:
Input: nums = [6,5,4,4]
Output: true

Example 3:
Input: nums = [1,3,2]
Output: false

Constraints:
1 <= nums.length <= 105
-105 <= nums[i] <= 105
=end

# @param {Integer[]} nums
# @return {Boolean}
defis_monotonic(nums)
x=nums
up=false
down=false
(1...x.size).eachdo |i|
returnfalseifup && down
up=trueifx[i - 1] < x[i]
down=trueifx[i - 1] > x[i]
end
returnfalseifup && down
true
end

# **************** #
# TEST #
# **************** #

require"test/unit"
classTest_is_monotonic < Test::Unit::TestCase
deftest_
assert_equaltrue,is_monotonic([1,2,2,3])
assert_equaltrue,is_monotonic([6,5,4,4])
assert_equalfalse,is_monotonic([1,3,2])
end
end