164. 最大间距

class Solution:
    def maximumGap(self, nums):
        """
        :type nums: List[int]
        :rtype: int
        """
        if len(nums) >= 2:
            max_gap = 0
            nums1 = sorted(list(set(nums)))
            for i in range(len(nums1)):
                gap = 0
                if i< len(nums1)-1:
                    a = nums1[i] - nums1[i+1]
                    if a>=0:
                        gap = a
                    else:
                        gap = -a
                max_gap = max(gap,max_gap)
            return max_gap
        else:
            return 0