摘要：
At the beginning of every day, the first person who signs in the computer room will unlock the door, and the last one who signs out will lock the door 阅读全文
摘要：
1005 Spell It Right 1005 Spell It Right 1005 Spell It Right Given a non-negative integer N, your task is to compute the sum of all the digits of N, an 阅读全文
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A family hierarchy is usually presented by a pedigree tree. Your job is to count those family members who have no child. Input Specification: Each inp 阅读全文
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这鬼题目就不能用Java来做。各种超时。TMD 还有莫名其妙的答案错误。总之没拿满分-.-。233 总体思路就是DFS。加栈回溯。 烦的要命。 阅读全文
