摘要:
某省自从实行了很多年的畅通工程计划后,终于修建了很多路。不过路多了也不好,每次要从一个城镇到另一个城镇时,都有许多种道路方案可以选择,而某些方案要比另一些方案行走的距离要短很多。这让行人很困扰。 相信大家都听说一个“百岛湖”的地方吧,百岛湖的居民生活在不同的小岛中,当... 阅读全文
摘要:
Bessie hears that an extraordinary meteor shower is coming; reports say that these meteors will crash into earth and destroy anything ... 阅读全文
摘要:
Alice and Bob play 5-in-a-row game. They have a playing field of size 10 × 10. In turns they put either crosses or noughts, one at a t... 阅读全文