code: def find_pairs(arr, K):
      # set to save all complements
      complements = set()
      # set to save all unique complements that form a pair
      pair_complements = set()
  
      for el in arr:
          c = K - el
  
          # if complement exists, then a pair is found
          if c in complements:
              pair_complements.add(c)
  
          # save this number as complement
          complements.add(el)
  
      # find all unique pairs
      pairs = []
      for c in pair_complements:
          pairs.append((c, K - c))
  
      return pairs
  
label_desc: Use image node_id 1 for calling a global function with example usage: find_pairs(arr, K) and returns: pairs