分类存档: ACM/ICPC - 第2页

ZJU 2876 解题报告

Phone List

Time Limit: 5 Seconds Memory Limit: 32768 KB

Given a list of phone numbers, determine if it is consistent in the sense that no number is the prefix of another. Let’s say the phone catalogue listed these numbers:
– Emergency 911
– Alice 97 625 999
– Bob 91 12 54 26

In this case, it’s not possible to call Bob, because the central would direct your call to the emergency line as soon as you had dialled the first three digits of Bob’s phone number. So this list would not be consistent.

Input

The first line of input gives a single integer, 1 <= t <= 40, the number of test cases. Each test case starts with n, the number of phone numbers, on a separate line, 1 <= n <= 10000.Then follows n lines with one unique phone number on each line. A phone number is a sequence of at most ten digits.

Output

For each test case, output “YES” if the list is consistent, or “NO” otherwise.

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ZJU 2829 解题报告

Beautiful Number

Time Limit: 1 Seconds Memory Limit: 32768 KB

Mike is very lucky, as he has two beautiful numbers, 3 and 5. But he is so greedy that he wants infinite beautiful numbers. So he declares that any positive number which is dividable by 3 or 5 is beautiful number. Given you an integer N (1 <= N <= 100000), could you please tell mike the Nth beautiful number?

Input

The input consists of one or more test cases. For each test case, there is a single line containing an integer N.

Output

For each test case in the input, output the result on a line by itself.

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ZJU 2723 解题报告

Semi-Prime

Time Limit: 1 Seconds Memory Limit: 32768 KB

Prime Number Definition

An integer greater than one is called a prime number if its only positive divisors (factors) are one and itself. For instance, 2, 11, 67, 89 are prime numbers but 8, 20, 27 are not.

Semi-Prime Number Definition

An integer greater than one is called a semi-prime number if it can be decompounded to TWO prime numbers. For example, 6 is a semi-prime number but 12 is not.

Your task is just to determinate whether a given number is a semi-prime number.

Input

There are several test cases in the input. Each case contains a single integer N (2 <= N <= 1,000,000)

Output

One line with a single integer for each case. If the number is a semi-prime number, then output “Yes”, otherwise “No”.

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ZJU 2744 解题报告

Palindromes

Time Limit: 1 Seconds Memory Limit: 32768 KB

A regular palindrome is a string of numbers or letters that is the same forward as backward. For example, the string “ABCDEDCBA” is a palindrome because it is the same when the string is read from left to right as when the string is read from right to left.

Now give you a string S, you should count how many palindromes in any consecutive substring of S.

Input

There are several test cases in the input. Each case contains a non-empty string which has no more than 5000 characters.Proceed to the end of file.

Output

A single line with the number of palindrome substrings for each case.

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SGU 276 解题报告

http://acm.sgu.ru/problem.php?contest=0&problem=276

276. Andrew’s Troubles

time limit per test: 1 sec.
memory limit per test: 65536 KB

Famous Berland ACM-ICPC team Anisovka consists of three programmers: Andrew, Michael and Ilya. A long time ago, during the first few months the team was founded, Andrew was very often late to the trainings and contests. To stimulate Andrew to be more punctual, Ilya and Andrew decided to introduce a new rule for team participants. If somebody is late (i.e. comes at least one second after appointed time) he owes a cup of tea to other team members. If he is late for 5 minutes, he owes two cups of tea. If he is late for 15 minutes, he owes three cups of tea. And if he is late for 30 minutes or more, he owes 4 cups of tea.

著名的 Berland ACM-ICPC 团队 Anisovka 包含三名成员:Andrew, Michael and Ilya.在团队刚建立的几个月里,Andrew 经常在比赛和训练中迟到.为了激励 Andrew 更加准时, Ilya 和 Andrew 决定在团队训练中引入一条新规则.如果有人迟到(即至少比约定的时间晚一秒) 则他欠团队其他成员一杯茶.如果他迟到5 分钟,他将欠 2 杯茶.如果他迟到 15 分钟,他将欠 3 杯茶.如果迟到 15 分钟惠更多,他将欠 4 杯茶.

The training starts at the time S (counted in seconds, from some predefined moment of time) and Andrew comes at the time P (also in seconds, counted from the same moment of time).

训练开始的时间是 S (以秒作为计时单位) Andrew到达的时间是 P (同样以秒作为计时单位).

Your task is to find how many cups of tea Andrew owes.

你的任务是计算出 Andrew 一共欠多少杯茶.

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SGU 222 解题报告

http://acm.sgu.ru/problem.php?contest=0&problem=222

222. Little Rooks

time limit per test: 1 sec.
memory limit per test: 65536 KB

Inspired by a “Little Bishops” problem, Petya now wants to solve problem for rooks.

A rook is a piece used in the game of chess which is played on a board of square grids. A rook can only move horizontally and vertically from its current position and two rooks attack each other if one is on the path of the other.

Given two numbers n and k, your job is to determine the number of ways one can put k rooks on an n × n chessboard so that no two of them are in attacking positions.

受小主教问题的启发, Petya现在决定解决一个关于车的问题.

车是国际象棋中的一种棋子,只能在水平和垂直方向移动,如果在一个移动方向上有两个车,他们就会互相攻击.

给定两个数n和k,你的工作是要计算出在n× n的棋盘中放置K个车,使他们不会相互攻击的方案数量.

Input

The input file contains two integers n (1 ≤ n ≤ 10) and k (0 ≤ k ≤ n2).

Output

Print a line containing the total number of ways one can put the given number of rooks on a chessboard of the given size so that no two of them are in attacking positions.

Sample Input

4 4

Sample Output

24

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SGU 304 解题报告

http://acm.sgu.ru/problem.php?contest=0&problem=302

302. BHTML 1.0

Time limit per test: 2 second(s)
Memory limit: 65536 kilobytes

The hypertext markup language BHTML 1.0 has only two paired tags. They are <UP> </UP> and <DOWN> </DOWN>. The <UP> </UP> tag capitalizes all letters inside its body (between an open tag and a close one), and <DOWN> </DOWN> makes all inside the body letters lowercase. You are given the text consisting of latin letters and tags. Your task is to write the text right as it will be shown in the Bernet Explorer browser window. Tags in the text are arranged correctly, i.e. they form correct bracket sequence. If a letter lays inside several tags, its case is defined by the most inner tag.

Input

The input contains the string S with the text. The length of the string is a natural number not exceeding 1000. Tags are always written in uppercase.

Output

Write to the output text after the processing.

Example(s)

sample input sample output
Thi<UP>sIs<DOWN>EaSY</DOWN>Pr<UP>O</UP>ble</UP>m ThiSISeasyPROBLEm

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ZJU 1109 解题报告

Language of FatMouse

Time Limit: 10 Seconds Memory Limit: 32768 KB

We all know that FatMouse doesn’t speak English. But now he has to be prepared since our nation will join WTO soon. Thanks to Turing we have computers to help him.

Input Specification

Input consists of up to 100,005 dictionary entries, followed by a blank line, followed by a message of up to 100,005 words. Each dictionary entry is a line containing an English word, followed by a space and a FatMouse word. No FatMouse word appears more than once in the dictionary. The message is a sequence of words in the language of FatMouse, one word on each line. Each word in the input is a sequence of at most 10 lowercase letters.

Output Specification

Output is the message translated to English, one word per line. FatMouse words not in the dictionary should be translated as “eh”.

Sample Input

dog ogday
cat atcay
pig igpay
froot ootfray
loops oopslay
atcay
ittenkay
oopslay

Output for Sample Input

cat
eh
loops

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SGU 114 解题报告

http://acm.sgu.ru/problem.php?contest=0&problem=114

114. Telecasting station

time limit per test: 0.50 sec.
memory limit per test: 4096 KB

Every city in Berland is situated on Ox axis. The government of the country decided to build new telecasting station. After many experiments Berland scientists came to a conclusion that in any city citizens displeasure is equal to product of citizens amount in it by distance between city and TV-station. Find such point on Ox axis for station so that sum of displeasures of all cities is minimal.

Input

Input begins from line with integer positive number N (0<N<15000) – amount of cities in Berland. Following N pairs (X, P) describes cities (0<X, P<50000), where X is a coordinate of city and P is an amount of citizens. All numbers separated by whitespace(s).

Output

Write the best position for TV-station with accuracy 10-5.

Sample Input

4
1 3
2 1
5 2
6 2

Sample Output

3.00000

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SGU 144 解题报告

http://acm.sgu.ru/problem.php?contest=0&problem=144

144. Meeting

time limit per test: 0.50 sec.
memory limit per test: 4096 KB

Two of the three members of the winning team of one of the ACM regional contests are going to meet in order to train for the upcoming World Finals. They decided that they will meet sometime between X o’clock and Y o’clock. Because they never get anywhere on time (they were late even on the day of the regional contest), they did not set an exact time when they will meet. However, they decided that the one who gets first at the meeting point will not wait more than Z minutes for the other one (they calculated that, if the other one will not come within Z minutes from the arrival of the first of them, then it is very probable that he will not show up at all).
Knowing that, in the end, both of them will show up at some time between X o’clock and Y o’clock (not necessarily after an integer number of minutes), compute which is the probability that they will actually meet.

Input

The input will contain 2 integer numbers X and Y (0<=X<Y<=24) and one real number Z ( 0 < Z <= 60*(Y-X) ).

Output

You should output the required probability with 7 decimal digits (rounded according to the 8th decimal digit).

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