Leetcode No.219 存在重复元素 II（滑动窗口）

class Solution(object):
    def containsNearbyDuplicate(self, nums, k):
        """
        :type nums: List[int]
        :type k: int
        :rtype: bool
        """
        n=len(nums)
        for i in range(0,n):
            for j in range(i+1,i+k+1 if i+k+1<=n else n):
                if(nums[i]==nums[j]):
                    return True
        return False

class Solution {
    public boolean containsNearbyDuplicate(int[] nums, int k) {
        int n=nums.length;
        Set set=new HashSet();
        for(int i=0;i<n;i++){
            if(set.contains(nums[i])){
                return true;
            }
            set.add(nums[i]);
            if(set.size()>k){
                set.remove(nums[i-k]);
            }
        }
        return false;
    }
}