Contains Duplicate II.py

'''
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.

Example 1:

Input: nums = [1,2,3,1], k = 3
Output: true

Example 2:

Input: nums = [1,0,1,1], k = 1
Output: true

Example 3:

Input: nums = [1,2,3,1,2,3], k = 2
Output: false


'''

class Solution(object):
    def containsNearbyDuplicate(self, nums, k):
        """
        :type nums: List[int]
        :type k: int
        :rtype: bool
        """
        dic = {}
        for i in xrange(len(nums)):
            if nums[i] not in dic:
                dic[nums[i]] = [i]
            else:
                if i - dic[nums[i]][-1] <= k:
                    return True
                dic[nums[i]].append(i)
                
        return False