Description
https://leetcode.com/problems/monotonic-array/
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
Explanation
Check if array is in either ascending or descending order.
Python Solution
class Solution:
def isMonotonic(self, A: List[int]) -> bool:
is_ascending = True
prev = None
for num in A:
if prev != None and num < prev:
is_ascending = False
prev = num
if is_ascending:
return True
is_descending = True
prev = None
for num in A:
if prev != None and num > prev:
print (num, prev)
is_descending = False
return False
prev = num
return is_descending
- Time Complexity: O(N).
- Space Complexity: O(1).