https://github.com/ZiyanGZiyaNG/Competitive-Programming/blob/main/%E5%AD%B8%E7%A7%91%E8%83%BD%E5%8A%9B%E7%AB%B6%E8%B3%BD/101%E5%AD%B8%E5%B9%B4%E5%BA%A6%20%E5%8C%97%E5%9F%BA%E5%8D%80%20%E8%B3%87%E8%A8%8A%E5%AD%B8%E7%A7%91%E8%83%BD%E5%8A%9B%E7%AB%B6%E8%B3%BD%20pA.cpp