摘要：
描述 Caocao was defeated by Zhuge Liang and ZhouYu in the battle of Chibi. But he wouldn't give up. Caocao's army still was not good at water battles, s 阅读全文
摘要：
描述 In order to make their sons brave, Jiajia and Wind take them to a big cave. The cave has n rooms, and one-way corridors connecting some rooms. Each 阅读全文
摘要：
描述 Every cow's dream is to become the most popular cow in the herd. In a herd of N (1 <= N <= 10,000) cows, you are given up to M (1 <= M <= 50,000) o 阅读全文