DFS——poj2034Anti-prime Sequences

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一、题目回顾

题目链接：Anti-prime Sequences

Description

Given a sequence of consecutive integers n,n+1,n+2,...,m, an anti-prime sequence is a rearrangement of these integers so that each adjacent pair of integers sums to a composite (non-prime) number. For example, if n = 1 and m = 10, one such anti-prime sequence is 1,3,5,4,2,6,9,7,8,10. This is also the lexicographically first such sequence.
We can extend the definition by defining a degree danti-prime sequence as one where all consecutive subsequences of length 2,3,...,d sum to a composite number. The sequence above is a degree 2 anti-prime sequence, but not a degree 3, since the subsequence 5, 4, 2 sums to 11. The lexicographically .rst degree 3 anti-prime sequence for these numbers is 1,3,5,4,6,2,10,8,7,9.         

一个由连续的整数（n,n+1,n+2,…,m）组成的序列，an anti-prime sequence就是这些整数的重新排列，使每一对相邻的整数与一个复合(非素数)数相加。例如，如果n = 1和m = 10，一个这样的anti-prime sequence就是1 3 5 4 2 6 9 7 8 10。 This is also the lexicographically first such sequence. 

我们可以通过定义一个danti - prime sequence来扩展这个定义，它的长度为2,3，…，d和一个复合数。上面的序列是2次反质数序列，而不是3次，因为子序列5、4、2和11。字母顺序进行的第3次反质数序列为1 3 5 4 6 2 10 8 7 9。

Input

DFS——poj2034Anti-prime Sequences

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原文地址：http://www.cnblogs.com/xzxl/p/7310265.html