219. Contains Duplicate II
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
思路:用字典存数组和下标dic[1]=0,存的时候,如果之前有值,比较新的值下标和之前的差,index-dic[1] <= k,如果小于,返回True,遍历完,返回False
代码:python3
class Solution:
def containsNearbyDuplicate(self, nums: List[int], k: int) -> bool:
dic = {}
for index,value in enumerate(nums):
if value not in dic:
dic[value] = index
else:
if index-dic[value] <= k:
return True
else:
dic[value] = index
return False
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