maraton.py

def solution(participant, completion):
  hash_map = {}
  length = len(completion)
  for i in range(length):
    c = completion[i]
    if hash_map.get(c) == None:
      hash_map[c] = 1
    else:
      hash_map[c] = hash_map[c] + 1
  
  for i in range(length+1):
    p = participant[i]
    if hash_map.get(p) == None:
      return p
    hash_map[p] = hash_map[p] + 1
    
  for key in hash_map.keys():
    if hash_map[key]%2 == 1:
      return key