Problem
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
Solution
/**
* @param {number[]} nums
* @return {boolean}
*/
var isMonotonic = function(nums) {
return nums.every((num, i) => i === 0 || nums[i - 1] <= num)
|| nums.every((num, i) => i === 0 || nums[i - 1] >= num);
};
Explain:
nope.
Complexity:
- Time complexity : O(n).
- Space complexity : O(1).