Roleta Romana - Solução em Python para o problema do dojo de PHP que ocorreu no dia 2013-01-15 na iMasters.

roleta.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""
Created on Wed Jan 16 01:17:27 2013
Copyright (C) 2012 Danilo de Jesus da Silva Bellini

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.

Especificacão do problema:
http://dojopuzzles.com/problemas/exibe/roleta-romana/
"""

import pytest
from collections import deque


def sobrevivente_roleta(pessoas, passos, inicio):
  vivos = deque(xrange(1, pessoas + 1))
  vivos.rotate(-inicio)
  while len(vivos) > 1:
    vivos.rotate(1 - passos)
    vivos.popleft()
  return vivos.popleft()


class TestRoleta(object):

  tabela_testes = [
    (1, 1, 1, 1),
    (2, 1, 1, 1),
    (2, 1, 2, 2),
    (2, 2, 1, 2),
    (2, 2, 2, 1),
    (3, 1, 1, 1),
    (3, 1, 2, 2),
    (3, 1, 3, 3),
    (3, 2, 1, 1),
    (3, 2, 2, 2),
    (3, 2, 3, 3),
    (3, 3, 1, 3),
    (3, 3, 2, 1),
    (3, 3, 3, 2),
    (4, 1, 1, 1),
    (4, 1, 2, 2),
    (4, 1, 3, 3),
    (4, 1, 4, 4),
    (4, 2, 1, 2),
    (4, 2, 2, 3),
    (4, 2, 3, 4),
    (4, 2, 4, 1),
    (4, 3, 1, 2),
    (4, 3, 2, 3),
    (4, 3, 3, 4),
    (4, 3, 4, 1),
    (4, 4, 1, 3),
    (4, 4, 2, 4),
    (4, 4, 3, 1),
    (4, 4, 4, 2),
    (5, 1, 1, 1),
    (5, 1, 2, 2),
    (5, 1, 3, 3),
    (5, 1, 4, 4),
    (5, 1, 5, 5),
    (5, 2, 1, 4),
    (5, 2, 2, 5),
    (5, 2, 3, 1),
    (5, 2, 4, 2),
    (5, 2, 5, 3),
    (5, 3, 1, 5),
    (5, 3, 2, 1),
    (5, 3, 3, 2),
    (5, 3, 4, 3),
    (5, 3, 5, 4),
    (5, 4, 1, 2),
    (5, 4, 2, 3),
    (5, 4, 3, 4),
    (5, 4, 4, 5),
    (5, 4, 5, 1),
    (5, 5, 1, 3),
    (5, 5, 2, 4),
    (5, 5, 3, 5),
    (5, 5, 4, 1),
    (5, 5, 5, 2),
  ]

  @pytest.mark.parametrize(("pessoas", "passos", "inicio", "saida"),
                           tabela_testes)
  def test_mapeamento_entrada_saida(self, pessoas, passos, inicio, saida):
    assert sobrevivente_roleta(pessoas, passos, inicio) == saida


if __name__ == "__main__":
  pytest.main('"%s"' % __file__)