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Problem DescriptionA ring is compose of n circles as shown in diagram. Put natural number 1, 2, ..., n into each circle separately, and the sum of numbers in two adjacent circles should be a prime.Note: the number of first circle should always be 1.Inputn (0 #include#includeint n;int arr[20];int vis 阅读全文
摘要：
Problem Description=== Op tech briefing, 2002/11/02 06:42 CST ==="The item is locked in a Klein safe behind a painting in the second-floor library. Klein safes are extremely rare; most of them, along with Klein and his factory, were destroyed in World War II. Fortunately old Brumbaugh from rese 阅读全文
摘要：
In Zhejiang University, there are N different courses labeled from 1 to N. Each course has its own time slot during the week. We can represent the time slot of a course by an left-closed right-open interval [s, t).Now we are going to arrange the final exam time of all the courses.The final exam peri 阅读全文