Leetcode 220: Contains Duplicate III

Posted 2020-10-16 Keep walking

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.

 

Note: C# type conversion is pretty tricky, the rule is to do conversion in all the places needed.

 1 public class Solution {
 2     public bool ContainsNearbyAlmostDuplicate(int[] nums, int k, int t) {
 3         if (t < 0 || k < 0) return false;
 4         
 5         long bucketLen = (long)t + 1;
 6         var dict = new Dictionary<long, long>();
 7         
 8         for (int i = 0; i < nums.Length; i++)
 9         {
10             long n = (long)((long)nums[i] - Int32.MinValue);
11             var key = n / bucketLen;
12             
13             if (dict.ContainsKey(key) || (dict.ContainsKey(key - 1) && (n - dict[key - 1] <= t)) || (dict.ContainsKey(key + 1) && (dict[key + 1] - n <= t)))
14             {
15                 return true;
16             }
17             
18             dict[key] = n;
19                                           
20             if (i >= k)
21             {
22                 dict.Remove((long)((long)nums[i - k] - Int32.MinValue) / bucketLen);
23             }
24         }
25         
26         return false;
27     }
28 }