I don't agree with official solution its way to complicated and not practice for interview session

class Solution:

  '''
    first sort the array 

    Then for each array element at i, j 

    add elements at i and j

    now we need to find the remaining elements 

    define start pointer that goes --> and pointer end that goes <-- to find the remaining elements 

    since the array is sorted we know when move a start or end pointer

    add the elements at position start and end and see if this + the i, j additions = target

    -3, -1, 1, 1, 1, 1, 1, 2, 4
     i   j  s  -->        <-- e
  '''
  def searchQuadruplets(self, arr, target):
    quadruplets = []
    seen = set()
    
    arr.sort()
    
    for i in range(len(arr) - 3):
      for j in range(i + 1, len(arr) - 2):
        add = arr[i] + arr[j]

        start = j + 1
        end = len(arr) - 1

        while start < end:
          remain_add = arr[start] + arr[end]
          
          quad = (arr[i], arr[j], arr[start], arr[end])

          if remain_add  == (target - add) and quad not in seen:
            quadruplets.append([arr[i], arr[j], arr[start], arr[end]])
            seen.add(quad)
            start += 1
            end -= 1

          elif remain_add > (target - add):
            end -= 1

          else:
            start += 1

    return quadruplets