Leetcode 665. Non-decreasing Array

注意判断[3,4,2,3]这种改不了的情况.

class Solution:
    def checkPossibility(self, nums: List[int]) -> bool:
        use=False
        for i in range(len(nums)-1):
            if nums[i]>nums[i+1]:
                if not use:
                    use=True
                    a=nums.copy()
                    a[i]=a[i+1]
                    b=nums.copy()
                    b[i+1]=b[i]
                    if (sorted(a)!=a) and (sorted(b)!=b):
                        return False
                else:
                    return False
        return True