public class Solution {    public int FindPairs(int[] nums, int k) {        var pair = new Dictionary
     
      ();            var list = nums.OrderBy(x => x).ToList();            for (int i = 0; i < list.Count; i++)            {                for (int j = i; j < list.Count; j++)                {                    if (i == j)                    {                        continue;                    }                    else                    {                        var dif = Math.Abs(list[i] - list[j]);                        if (dif > k)                        {                            break;                        }                        if (dif == k)                        {                            if ((!pair.ContainsKey(list[i] + "|" + list[j])) && (!pair.ContainsKey(list[j] + "|" + list[i])))                            {                                pair.Add(list[i] + "|" + list[j], i + "|" + j);                            }                        }                    }                }            }            var result = pair.Count();            return result;    }}