# -*- coding: utf-8 -*-

"""

Given an array with n integers, your task is to check if it could become non-decreasing by modifying at most 1 element.

We define an array is non-decreasing if array[i] <= array[i + 1] holds for every i (1 <= i < n).

Example 1:

Input: [4,2,3]

Output: True

Explanation: You could modify the first 4 to 1 to get a non-decreasing array.

Example 2:

Input: [4,2,1]

Output: False

Explanation: You can't get a non-decreasing array by modify at most one element.

Note: The n belongs to [1, 10,000].

"""

class Solution:

def checkPossibility(self, nums):

"""

:type nums: List[int]

:rtype: bool

>>> test1 = [4,2,3]

>>> test2 = [4,2,1]

>>> s = Solution()

>>> s.checkPossibility(test1)

True

>>> s.checkPossibility(test2)

False

"""

l = len(nums)

count = 0

for i in range(l - 1):

if nums[i] > nums[i + 1]:

count += 1

if i == 0:

nums[i] = nums[i + 1]

elif nums[i - 1] <= nums[i + 1]:

nums[i] = nums[i - 1]

else:

nums[i + 1] = nums[i]

if count > 1:

return False

return True

if __name__ == '__main__':

import doctest

doctest.testmod(verbose=True)