LeetCode 896. Monotonic Array

class Solution {
public:
    bool isMonotonic(vector<int> &A) {
        int n = A.size();
        bool inc = true, dec = true;
        for (int i = 0; i < n - 1; ++i) {
            if (A[i] > A[i + 1]) inc = false;
            if (A[i] < A[i + 1]) dec = false;
        }
        return inc || dec;
    }
};