LC896.cpp

/*
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
Example 4:

Input: nums = [1,2,4,5]
Output: true
Example 5:

Input: nums = [1,1,1]
Output: true

*/


class Solution {
public:
    bool isMonotonic(vector<int>& A) {

        bool isNonDecreasing = true;
        bool isNonIncreasing = true;
        
        for (int i = 1; i < A.size(); i++)
        {
            if (A[i] < A[i - 1])
                isNonDecreasing = false;
            if (A[i] > A[i - 1])
                isNonIncreasing = false;
        }
        
        return isNonDecreasing | isNonIncreasing;
    }
};