Invalid_Pointer的专栏

Parentheses Balance You are given a string consisting of parentheses () and [].    A string of this type is said to be correct: (a)if it is the empty string(b)if A and B are correct, AB

Problem B: Andy's First Dictionary Time limit: 3 seconds Andy, 8, has a dream - he wants to produce his very own dictionary. This is not an easy task for him, as the number of wo

Problem A Decode the tape Time Limit: 1 second "Machines take me by surprise with great frequency." Alan Turing Your boss has just unearthed a roll of old computer tapes. The

Searching Quickly Background Searching and sorting are part of the theory and practice of computer science.  For example, binary search provides a good example of an easy-to-understa

``Accordian'' Patience You are to simulate the playing of games of ``Accordian'' patience, the rules  for which are as follows: Deal cards one by one in a row from left to right, not overl

The Blocks Problem Background Many areas of Computer Science use simple, abstract domains  for both analytical and empirical studies.  For example, an early AI study of planning and ro

The Dole Queue In a serious attempt to downsize (reduce) the dole queue, The New National Green Labour Rhinoceros Party has decided on the following strategy.  Every day all dole applican

Tree You are to determine the value of the leaf node in a given binary tree that is the terminal node of a path of least value from the root of the binary tree to any leaf. The value of a path is th

Problem D: ShellSort He made each turtle stand on another one's back And he piled them all up in a nine-turtle stack. And then Yertle climbed up. He sat down on the pile. What a wonderful view! H

Problem E: Automatic Editing Source file: autoedit.{c, cpp,java, pas} Input file: autoedit.in Output file: autoedit.out Text-processing tools like awk and sed allow you

Team Queue Queues and Priority Queues are data structures which are known to most computer scientists. TheTeam Queue, however, is not so well known, though it occurs often in everyday lif

Matrix Chain Multiplication Suppose you have to evaluate an expression like A*B*C*D*E where A,B,C,D and E are matrices. Since matrix multiplication is associative, the order in which mult

Problem B - Generalized Matrioshkas Vladimir worked for years making matrioshkas, those nesting dolls that certainly represent truly Russian craft. A matrioshka is a doll that may be op

Quadtrees A quadtree is a representation format used to encode images. The fundamental idea behind the quadtree is that any image can be split into four quadrants. Each quadrant may again be

The Falling Leaves Each year, fall in the North Central region is accompanied by the brilliant colors of the leaves on the trees, followed quickly by the falling leaves accumulating under the tre

Tree Summing Background LISP was one of the earliest high-level programming languages and, with FORTRAN, is one of the oldest languages currently being used.  Lists, which are the

Oil Deposits The GeoSurvComp geologic survey company is responsible for detecting underground oil deposits. GeoSurvComp works with one large rectangular region of land at a time, and creates

Problem C If We Were a Child Again Input: standard input Output: standard output Time Limit: 7 seconds “Oooooooooooooooh! If I  could do the easy mathematics like my school days!! I can

Ananagrams Most crossword puzzle fans are used to anagrams--groups of words with the same letters in different orders--for example OPTS, SPOT, STOP, POTS and POST. Some words however do not h

Master-Mind Hints MasterMind is a game for two players.  One of them, Designer, selects a secret code.  The other,  Breaker, tries to break it.  A code is no more than a row of colored dots.

487-3279 Businesses like to have memorable telephone numbers. One way to make a telephone number memorable is to have it spell a memorable word or phrase. For example, you can call the Un

Unix ls The computer company you work for is introducing a brand new computer  line and is developing a new Unix-like operating system to be  introduced along with the new computer.  Your

Train Swapping At an old railway station, you may still encounter one of the last remaining ``train swappers''. A train swapper is an employee of the railroad, whose sole job it is to rearran

Where is the Marble? Raju and Meena love to play with Marbles. They have got a lot of marbles with numbers written on them. At the beginning, Raju would place the marbles one after anothe

Stacks of Flapjacks Background Stacks and Queues are often considered the bread and butter of data structures and find use in architecture, parsing, operating systems, and discrete eve

Immediate Decodability An encoding of a set of symbols is said to be immediately decodable if no code for one symbol is  the prefix of a code for another symbol.  We will assume for this problem that

Tree's a Crowd Dr William Larch, noted plant psychologist and inventor of the phrase ``Think like a tree--Think Fig'' has invented a new classification system for trees. This is a complicated

Product The Problem The problem is to multiply two integers X, Y. (0250) The Input The input will consist of a set of pairs of lines. Each line in pair contains one multiplye

Exponentiation Problems involving the computation of exact values of very large magnitude and precision are common. For example, the computation of the national debt is a taxing experience fo

Problem B List of Conquests Input:standard input Output: standard output Time Limit: 2 seconds In Act I, Leporello is telling Donna Elvira about his master's long list of conquests: ``This is

Overflow Write a program that reads an expression consisting of two non-negative integer and an operator. Determine if either integer or the result of the expression is too large to be represented

Integer Inquiry One of the first users of BIT's new supercomputer was Chip Diller. He extended his exploration of powers of 3 to go from 0 to 333 and he explored taking various sums of th

Excuses, Excuses! Judge Ito is having a problem with people subpoenaed for jury duty giving rather lame excuses in order to avoid serving. In order to reduce the amount of time required listening to