Medium

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

Example 1:

Input: nums = [1,2,3,1], k = 3, t = 0
Output: true

Example 2:

Input: nums = [1,0,1,1], k = 1, t = 2
Output: true

Example 3:

Input: nums = [1,5,9,1,5,9], k = 2, t = 3
Output: false

思路：采用桶排序，差值在t范围内的尽量放在同一个桶里，尽管如此也可能存在相邻的桶里，因此，每次也要把相邻的桶考虑进去；把窗口大小维持不超过k;

class Solution {
    public boolean containsNearbyAlmostDuplicate(int[] nums, int k, int t) {
        if(nums==null || nums.length<2 || k<1 || t<0) return false;
        Map<Long,Long> map = new HashMap<>();
        for(int i=0;i<nums.length;i++){
            long temp = (long)nums[i] - Integer.MIN_VALUE;//数组可能存在负数
            long bucket = temp/((long)t+1);//防止t+1溢出
            if(map.containsKey(bucket)||(map.containsKey(bucket-1)&&temp-map.get(bucket-1)<=t)||(map.containsKey(bucket+1)&&map.get(bucket+1)-temp<=t)) //如果是把(bucket,nums[i])加到map中的话，会有nums[i]-map.get(bucket-1)，在这里必须转long型，否则溢出
                return true;
            if(map.entrySet().size()>=k){维持在加进元素后窗口大小不超过k
                long invalid = ((long)nums[i-k] - Integer.MIN_VALUE)/((long)t+1);
                map.remove(invalid);
            }
            map.put(bucket,temp);
        }
        return false;
    }
}