這道題為簡單題

　　題目：

　　　　Given an array of integers and an integer k, find out whether there are two distinct indices i and j in the array such that nums[i] = nums[j] and the absolute difference between i and j is at most k.

　　思路：

　　　　利用字典，如果該元素存在於字典中，就判斷是否這兩個的索引值的絕對值是否小於等於k，如果沒有小於就添加或更改字典的鍵值

　　代碼：

 1
 
 class Solution(object):
 2     def containsNearbyDuplicate(self, nums, k):
 3         """
 4         :type nums: List[int]
 5         :type k: int
 6         :rtype: bool
 7         """
 8         b = {}
 9         for i in range(len(nums)):
10             if nums[i] in b and abs(b[nums[i]] - i) <= k:
 
11                     return True
12             b[nums[i]] = i
13         return False

Contains Duplicate II