896. Monotonic Array （easy）

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

 

Note:

 

1. 1 <= A.length <= 50000
2. -100000 <= A[i] <= 100000

 1 依舊萬能排序解法。。not fast

注意python3 reversed返回迭代器，加一個list轉成列表再判斷

class Solution:
    def isMonotonic(self, A):
        """
        :type A: List[int]
        :rtype: bool
        """
        sortA = sorted(A)
        if(A == sortA or sortA == list(reversed(A))): return True
        return False