日度归档：30 5 月, 2017

数据结构 邓俊辉 PA#4 循环移位(Cycle) 题解

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循环移位(Cycle)

Description

Cycle shifting refers to following operation on the sting. Moving first letter to the end and keeping rest part of the string. For example, apply cycle shifting on ABCD will generate BCDA. Given any two strings, to judge if arbitrary times of cycle shifting on one string can generate the other one.

Input

There m lines in the input, while each one consists of two strings separated by space. Each string only contains uppercase letter ‘A’~’Z’.

Output

For each line in input, output YES in case one string can be transformed into the other by cycle shifting, otherwise output NO.

Example

Input

AACD CDAA
ABCDEFG EFGABCD
ABCD ACBD
ABCDEFEG ABCDEE

Output

YES
YES
NO
NO

Restrictions

0 <= m <= 5000

1 <= |S1|, |S2| <= 10^5

Time: 2 sec

Memory: 256 MB

描述

所谓循环移位是指。一个字符串的首字母移到末尾, 其他字符的次序保持不变。比如ABCD经过一次循环移位后变成BCDA

给定两个字符串，判断它们是不是可以通过若干次循环移位得到彼此

输入

由m行组成，每行包含两个由大写字母’A’~’Z’组成的字符串，中间由空格隔开

输出

对于每行输入，输出这两个字符串是否可以通过循环移位得到彼此：YES表示是，NO表示否

样例

见英文题面

限制

0 ≤ m ≤ 5000

1 ≤ |S1|, |S2| ≤ 10^5

时间：2 sec

内存：256 MB

开心死啦！本来就觉得这道题必须写KMP来着，结果搞了个c++stl糊弄过去了……还好THUOJ没有删掉头文件 /笑，倒是其他的map list queue还有什么 algorithm 都删啦！ /偷笑 /捂脸
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Openjudge 画家问题

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画家问题

总时间限制:
1000ms
内存限制:
65536kB
描述
有一个正方形的墙，由N*N个正方形的砖组成，其中一些砖是白色的，另外一些砖是黄色的。Bob是个画家，想把全部的砖都涂成黄色。但他的画笔不好使。当他用画笔涂画第(i, j)个位置的砖时， 位置(i-1, j)、 (i+1, j)、 (i, j-1)、 (i, j+1)上的砖都会改变颜色。请你帮助Bob计算出最少需要涂画多少块砖，才能使所有砖的颜色都变成黄色。

输入
第一行是一个整数n (1≤n ≤15)，表示墙的大小。接下来的n行表示墙的初始状态。每一行包含n个字符。第i行的第j个字符表示位于位置(i,j)上的砖的颜色。“w”表示白砖，“y”表示黄砖。
输出
一行，如果Bob能够将所有的砖都涂成黄色，则输出最少需要涂画的砖数，否则输出“inf”。
样例输入
5
wwwww
wwwww
wwwww
wwwww
wwwww
样例输出
15
来源
1681

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Openjudge Calling Extraterrestrial Intelligence Again 题解

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Calling Extraterrestrial Intelligence Again

总时间限制:
1000ms
内存限制:
65536kB
描述
A message from humans to extraterrestrial intelligence was sent through the Arecibo radio telescope in Puerto Rico on the afternoon of Saturday November 16, 1974. The message consisted of 1679 bits and was meant to be translated to a rectangular picture with 23 x 73 pixels. Since both 23 and 73 are prime numbers, 23 x 73 is the unique possible size of the translated rectangular picture each edge of which is longer than 1 pixel. Of course, there was no guarantee that the receivers would try to translate the message to a rectangular picture. Even if they would, they might put the pixels into the rectangle incorrectly. The senders of the Arecibo message were optimistic.

We are planning a similar project. Your task in the project is to find the most suitable width and height of the translated rectangular picture. The term “most suitable” is defined as follows. An integer m greater than 4 is given. A positive fraction a/b less than or equal to 1 is also given. The area of the picture should not be greater than m. Both of the width and the height of the translated picture should be prime numbers. The ratio of the width to the height should not be less than a/b nor greater than 1. You should maximize the area of the picture under these constraints.

In other words, you will receive an integer m and a fraction a/b. It holds that m > 4 and 0 < a/b <= 1. You should find the pair of prime numbers p, q such that pq <= m and a/b <= p/q <= 1, and furthermore, the product pq takes the maximum value among such pairs of two prime numbers. You should report p and q as the “most suitable” width and height of the translated picture.

输入
The input is a sequence of at most 2000 triplets of positive integers, delimited by a space character in between. Each line contains a single triplet. The sequence is followed by a triplet of zeros, 0 0 0, which indicates the end of the input and should not be treated as data to be processed.

The integers of each input triplet are the integer m, the numerator a, and the denominator b described above, in this order. You may assume 4 < m <= 100000 and 1 <= a <= b <= 1000.

输出
The output is a sequence of pairs of positive integers. The i-th output pair corresponds to the i-th input triplet. The integers of each output pair are the width p and the height q described above, in this order.

Each output line contains a single pair. A space character is put between the integers as a delimiter. No other characters should appear in the output.

样例输入
5 1 2
99999 999 999
1680 5 16
1970 1 1
2002 4 11
0 0 0
样例输出
2 2
313 313
23 73
43 43
37 53
来源
Japan 2002 Kanazawa

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