Monotonic array
Question
Can you check if a given array containing n integers is monotonic? Your function should return "true" if it is monotonic and "false" if it's not.
An array is monotonic if it is either monotone increasing or monotone decreasing. An array A is monotone increasing if for all i <= j, A[i] <= A[j]. An array A is monotone decreasing if for all i <= j, A[i] >= A[j].
For example:
Input : [6, 5, 4, 4]
Output : true
Input : [5, 5, 5, 4]
Output : true
Input : [5, 15, 20, 10]
Output : false