KMP

Theme Section(HDU-4763) 题面 It’s time for music! A lot of popular musicians are invited to join us in the music festival. Each of them will play one of their representative songs. To make the programs more interesting and challenging, the hosts are going to add some constraints to the rhythm of the songs, i.e., each song is required to have a ’theme section’. The theme section shall be played at the beginning, the middle, and the end of each song. More specifically, given a theme section E, the song will be in the format of ‘EAEBE’, where section A and section B could have arbitrary number of notes. Note that there are 26 types of notes, denoted by lower case letters ‘a’ - ‘z’. ...

Wow! Such Doge!(HDU-4847) 题面 Chen, Adrian (November 7, 2013). “Doge Is An Ac- tually Good Internet Meme. Wow.”. Gawker. Retrieved November 22, 2013. Doge is an Internet meme that became popular in 2013. The meme typically con- sists of a picture of a Shiba Inu dog ac- companied by multicolored text in Comic Sans MS font in the foreground. The text, representing a kind of internal monologue, is deliberately written in broken English, and usually contains the word “wow” and the phrases “such x”, “much x”, “many x”, “very x” and “so x”. Kabosu, the Shiba Inu featured in the original meme, was first pictured in a 2010 blog post by Atsuko Sato, a Japanese kindergarten teacher. Afterwards, varia- tions of the pictures using overlaid Comic Sans text were posted from a Tumblr blog, Shiba Confessions. However, the use of the intentionally misspelled “doge” dates back to June 2005, when it was mentioned in an episode of Homestar Runners puppet series. In August 2013, images of the meme were spammed on Reddit’s r/MURICA subreddit by 4chan’s random imageboard, /b/. A search of the term doge on Google Trends shows an explosion of popularity occurring in October 2013, and more so in the following month. By November 2013, the meme had become widespread on the Internet. Google later created a Doge Easter egg: when doge meme was entered into the YouTube search bar, all of the site’s text would be displayed in colorful Comic Sans, similar to the kind used by the meme. The meme was ranked #12 on MTV’s list of “50 Things Pop Culture Had Us Giving Thanks For” in 2013. Io9 compared the internal dialog of the Shiba Inu dogs to lolcat-speak. The image most commonly associated with the meme is of a female Shiba Inu named Kabosu, taken from a Japanese blog documenting the dog’s daily activities. The spelling of doge has several variants, leading to debate on its actual pronunciation. On December 13, Doge was named the “top meme” of 2013 by Know Your Meme. In December 2013, the Dogecoin was introduced as a new cryptocurrency, making it the first cryptocurrency to be based on an Internet meme; the viral phenomenon, along with usage of the Comic Sans MS typeface, gave it “the Internet density of a large star” according to Medium writer Quinn Norton. In late December 2013, members of the U.S. Congress produced material in the meme’s style. Huffington Post commented that Doge was “killed” because of the Congress members’ usage of the meme. By early 2014, Doge’s popularity was sustained by internet communities on social media, accompanied by the rapid growth and acceptance of Dogecoin. In April 2014, Doge experienced a second major media resurgence due to revelations of the Dogecoin community’s intent to sponsor Josh Wise in NASCAR and place a picture of the Shiba Inu on his vehicle. ...

Period II(FZU-1901) 题面 For each prefix with length P of a given string S,if S[i]=S[i+P] for i in [0..SIZE(S)-p-1], then the prefix is a “period” of S. We want to all the periodic prefixs. 输入 Input contains multiple cases. The first line contains an integer T representing the number of cases. Then following T cases. Each test case contains a string S (1 <= SIZE(S) <= 1000000),represents the title.S consists of lowercase ,uppercase letter. ...

String Problem(HDU-3374) 题面 Give you a string with length N, you can generate N strings by left shifts. For example let consider the string “SKYLONG”, we can generate seven strings: String Rank SKYLONG 1 KYLONGS 2 YLONGSK 3 LONGSKY 4 ONGSKYL 5 NGSKYLO 6 GSKYLON 7 and lexicographically first of them is GSKYLON, lexicographically last is YLONGSK, both of them appear only once. Your task is easy, calculate the lexicographically fisrt string’s Rank (if there are multiple answers, choose the smallest one), its times, lexicographically last string’s Rank (if there are multiple answers, choose the smallest one), and its times also. ...

Corporate Identity(HDU-2328) 题面 Beside other services, ACM helps companies to clearly state their “corporate identity”, which includes company logo but also other signs, like trademarks. One of such companies is Internet Building Masters (IBM), which has recently asked ACM for a help with their new identity. IBM do not want to change their existing logos and trademarks completely, because their customers are used to the old ones. Therefore, ACM will only change existing trademarks instead of creating new ones. ...

Substrings(HDU-1238) 题面 You are given a number of case-sensitive strings of alphabetic characters, find the largest string X, such that either X, or its inverse can be found as a substring of any of the given strings. 输入 The first line of the input file contains a single integer t (1 <= t <= 10), the number of test cases, followed by the input data for each test case. The first line of each test case contains a single integer n (1 <= n <= 100), the number of given strings, followed by n lines, each representing one string of minimum length 1 and maximum length 100. There is no extra white space before and after a string. ...

Clairewd’s message(HDU-4300) 题面 Clairewd is a member of FBI. After several years concealing in BUPT, she intercepted some important messages and she was preparing for sending it to ykwd. They had agreed that each letter of these messages would be transfered to another one according to a conversion table. Unfortunately, GFW(someone’s name, not what you just think about) has detected their action. He also got their conversion table by some unknown methods before. Clairewd was so clever and vigilant that when she realized that somebody was monitoring their action, she just stopped transmitting messages. But GFW knows that Clairewd would always firstly send the ciphertext and then plaintext(Note that they won’t overlap each other). But he doesn’t know how to separate the text because he has no idea about the whole message. However, he thinks that recovering the shortest possible text is not a hard task for you. Now GFW will give you the intercepted text and the conversion table. You should help him work out this problem. ...

Count the string(HDU-3336) 题面 It is well known that AekdyCoin is good at string problems as well as number theory problems. When given a string s, we can write down all the non-empty prefixes of this string. For example: s: “abab” The prefixes are: “a”, “ab”, “aba”, “abab” For each prefix, we can count the times it matches in s. So we can see that prefix “a” matches twice, “ab” matches twice too, “aba” matches once, and “abab” matches once. Now you are asked to calculate the sum of the match times for all the prefixes. For “abab”, it is 2 + 2 + 1 + 1 = 6. The answer may be very large, so output the answer mod 10007. ...

Simpsons’ Hidden Talents(HDU-2594) 题面 Homer: Marge, I just figured out a way to discover some of the talents we weren’t aware we had. Marge: Yeah, what is it? Homer: Take me for example. I want to find out if I have a talent in politics, OK? Marge: OK. Homer: So I take some politician’s name, say Clinton, and try to find the length of the longest prefix in Clinton’s name that is a suffix in my name. That’s how close I am to being a politician like Clinton Marge: Why on earth choose the longest prefix that is a suffix??? Homer: Well, our talents are deeply hidden within ourselves, Marge. Marge: So how close are you? Homer: 0! Marge: I’m not surprised. Homer: But you know, you must have some real math talent hidden deep in you. Marge: How come? Homer: Riemann and Marjorie gives 3!!! Marge: Who the heck is Riemann? Homer: Never mind. Write a program that, when given strings s1 and s2, finds the longest prefix of s1 that is a suffix of s2. ...

Blue Jeans (POJ-3080) 题面 The Genographic Project is a research partnership between IBM and The National Geographic Society that is analyzing DNA from hundreds of thousands of contributors to map how the Earth was populated. As an IBM researcher, you have been tasked with writing a program that will find commonalities amongst given snippets of DNA that can be correlated with individual survey information to identify new genetic markers. A DNA base sequence is noted by listing the nitrogen bases in the order in which they are found in the molecule. There are four bases: adenine (A), thymine (T), guanine (G), and cytosine (C). A 6-base DNA sequence could be represented as TAGACC. ...

Power Strings (POJ-2406) 题面 Given two strings a and b we define ab to be their concatenation. For example, if a = “abc” and b = “def” then ab = “abcdef”. If we think of concatenation as multiplication, exponentiation by a non-negative integer is defined in the normal way: a^0 = "" (the empty string) and a^(n+1) = a*(a^n). 输入 Each test case is a line of input representing s, a string of printable characters. The length of s will be at least 1 and will not exceed 1 million characters. A line containing a period follows the last test case. ...

Period (HDU-1358) 题面 For each prefix of a given string S with N characters (each character has an ASCII code between 97 and 126, inclusive), we want to know whether the prefix is a periodic string. That is, for each i (2 <= i <= N) we want to know the largest K > 1 (if there is one) such that the prefix of S with length i can be written as AK , that is A concatenated K times, for some string A. Of course, we also want to know the period K. ...

Cyclic Nacklace (HDU-3746) 题面 CC always becomes very depressed at the end of this month, he has checked his credit card yesterday, without any surprise, there are only 99.9 yuan left. he is too distressed and thinking about how to tide over the last days. Being inspired by the entrepreneurial spirit of “HDU CakeMan”, he wants to sell some little things to make money. Of course, this is not an easy task. ...

剪花布条 (HDU-2087) 题面 一块花布条，里面有些图案，另有一块直接可用的小饰条，里面也有一些图案。对于给定的花布条和小饰条，计算一下能从花布条中尽可能剪出几块小饰条来呢？ ...

Number Sequence (HDU-1711) 题面 Given two sequences of numbers : a[1], a[2], …… , a[N], and b[1], b[2], …… , b[M] (1 <= M <= 10000, 1 <= N <= 1000000). Your task is to find a number K which make a[K] = b[1], a[K + 1] = b[2], …… , a[K + M - 1] = b[M]. If there are more than one K exist, output the smallest one. ...

简介 Knuth-Morris-Pratt字符串查找算法，简称为“KMP算法”，常用于在一个文本串S内查找一个模式串T的出现位置。这个算法由Donald Knuth、Vaughan Pratt、James H. Morris三人于1977年联合发表，故取这3人的姓氏命名此算法。时间复杂度O(|S|+|T|)。 ...

Seek the Name, Seek the Fame (POJ-2752) 题面 The little cat is so famous, that many couples tramp over hill and dale to Byteland, and asked the little cat to give names to their newly-born babies. They seek the name, and at the same time seek the fame. In order to escape from such boring job, the innovative little cat works out an easy but fantastic algorithm: Step1. Connect the father’s name and the mother’s name, to a new string S. Step2. Find a proper prefix-suffix string of S (which is not only the prefix, but also the suffix of S). ...

Oulipo (HDU - 1686) 题面 The French author Georges Perec (1936–1982) once wrote a book, La disparition, without the letter ’e’. He was a member of the Oulipo group. A quote from the book: Tout avait Pair normal, mais tout s’affirmait faux. Tout avait Fair normal, d’abord, puis surgissait l’inhumain, l’affolant. Il aurait voulu savoir où s’articulait l’association qui l’unissait au roman : stir son tapis, assaillant à tout instant son imagination, l’intuition d’un tabou, la vision d’un mal obscur, d’un quoi vacant, d’un non-dit : la vision, l’avision d’un oubli commandant tout, où s’abolissait la raison : tout avait l’air normal mais… ...