title

problem link

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].

Return true if and only if the given array A is monotonic.

Example 1:

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

Input: [6,5,4,4]
Output: true
Example 3:

Input: [1,3,2]
Output: false
Example 4:

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

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

solution

judge whether sort

class Solution {
public:
	bool isMonotonic(vector<int>& A) {
		bool is1 = true, is2 = true;
		for (int i = 1; i < A.size(); i++) {
			if (A[i] < A[i - 1]) {
				is1 = false;
			}
		}
		for (int i = 1; i < A.size(); i++) {
			if (A[i]> A[i - 1]) {
				is2 = false;
			}
		}
		return is1 || is2;
	}
};