input: Write a python function to create comparisons lists based on given structure and comparison type.
  assert crea_comparacion([['1', 'A'], ['2', 'B'], ['3', 'C']], 'star', 'bi') == [['C', 'A'], ['A', 'C'], ['C', 'B'], ['B', 'C']]
  assert crea_comparacion([['1', 'A'], ['2', 'B'], ['3', 'C']], '1-2,1-3', 'uni') == [['B', 'C']]
  assert crea_comparacion([['1', 'A'], ['2', 'B'], ['3', 'C']], '1-2', 'bi') == [['A', 'B'], ['B', 'A']]
output: def crea_comparacion(lista, estructura, tipo):
      result = []
      if estructura == 'star':
          for i in range(1, len(lista)):
              if tipo == 'bi':
                  result.append([lista[i][1], lista[0][1]])
                  result.append([lista[0][1], lista[i][1]])
              elif tipo == 'uni':
                  result.append([lista[i][1], lista[0][1]])
      else:
          pairs = estructura.split(',')
          for pair in pairs:
              a, b = map(int, pair.split('-'))
              if tipo == 'bi':
                  result.append([lista[a-1][1], lista[b-1][1]])
                  result.append([lista[b-1][1], lista[a-1][1]])
              elif tipo == 'uni':
                  result.append([lista[a-1][1], lista[b-1][1]])
      return result