The algorithm design manual steven s. skiena pdf download

Elementary does not necessarily mean easy, however! These problems provide a good introduction to the demanding nature of the robot judge, and the need to read carefully and understand specifications.

They also provide an opportunity to discuss programming styles best suited to getting the job done. To help you get started, we begin with a description of the robot judges and their idiosyncrasies. We follow with a discussion of basic programming style and data struc- tures before introducing our first set of problems. As in all chapters in this book, we follow with hints for selected problems and notes for further study. All the problems in the book can be judged from either website, which are both administered by Miguel Revilla.

Be aware that both sites are living, breathing projects, so these procedures may evolve over time. Check the current instructions at each site for clarification. Getting Started Your first task is to get an account for the judge of your choice. You will be asked to give a password governing access to your personal data, specifically your name and your email address. If you forget your password, clicking the appropriate button will get it emailed back to you.

Note that the contestant rosters of the two sites are currently kept distinct, but there is no reason why you should not register for both of them and enjoy their distinct advantages. For example, a description of each challenge appearing in the book is given on site, along with down-loadable input and output files to eliminate the need for you to type this test data.

The Programming Challenges site uses a web interface for submission the Submit- o-Matic instead of the email interface of the UVa judge. This makes submission much easier and more reliable, and provides for quicker response.

Each problem in this book has two associated ID numbers, one for each judge. One advantage of the web interface is that the identifier for the Programming Challenges site the PC ID is not necessary for most submissions. However, the problems they describe are identical. Thus any solution scored as correct on one judge should be scored correct on the other as well.

The Programming Challenges site has a special course management interface, which permits an instructor to maintain a roster of students in each class and see their submis- sions and results. It also contains a program similarity tester so the instructor can verify that the solutions each student submits are indeed his or her own work. We encourage anyone whose appetite has been whetted by our challenges to continue their studies there.

After registering on the UVa judge, you will receive email containing an ID number which will uniquely identify your programs to the judge. You will need this ID number for every solution you submit. The UVa judge is gradually adopting a web interface but currently uses email submis- sion. Solutions are emailed directly to judge uva. Usually, this line is placed inside a comment. This is followed by the problem number in the example , and then by the language used.

Make sure you use the UVa ID number for all submissions to this judge! Upper- and lowercase letters are indistinguishable. If you fail to specify the programming language, the judge will try to auto-detect it — but why play games? It is very important to interpret the problem specifications properly. Never make an assumption which is not explicitly stated in the specs. There is absolutely no reason to believe that the input is sorted, the graphs are connected, or that the integers used in a problem are positive and reasonably small unless it says so in the specification.

Just like the human judges of the ACM International Collegiate Programming Con- test, the online judge provides you with very little feedback about what is wrong with your program. Your program is correct, and runs within the given time and memory limits. Usually your problems are something as trivial as an extra blank at the end of a line, so stop here and declare victory. You have some more debugging to do. The resulting compiler messages will be returned to you. Warning messages that do not interfere with compilation are ignored by the judge.

Its dying message will be sent back to you. Check for invalid pointer references or division by zero. Just because you ran out of time on one input does not mean you were correct on all the others, however! This usually means it is trapped in a infinite loop. Behave yourself. Just to reiterate: if your program is found guilty of having a wrong answer, the judge will not show you which test case it failed on, or give you any additional hints as to why it failed.

This is why it is so essential to review the specifications carefully. Even when you may be sure that your program is correct, the judge may keep saying no.

Resubmitting the program without change does you absolutely no good. Read the problem again to make sure it says what you thought it did. The judge occasionally returns a more exotic verdict which is essentially independent of your solution. See the appropriate website for details. Most likely, the language which you know best.

One pro- gramming language may well be better than another for a specific programming task. Its pop- ularity has eroded almost to the point of extinction, but it retains a foothold in high schools and in Eastern Europe.

This includes the power to hang yourself by invalid pointer references and invalid type casting. Developments in object-oriented programming during the s lead to the new and improved.

It is a full-featured programming language which can do everything the others can and more. Thus a program which runs on your machine may not run on the judge. It is interesting to look at which languages people have been using. As of December over 1,, program submissions have been sent to the robot judge.

Only a tiny fraction were written in Java, but that is not a fair test since the judge did not accept Java programs until November These submissions are broken down by month in Figure 1. It is interesting to note the annual spike in demand each fall as students train for the ACM International Collegiate Programming Contest regional competitions.

Every year the judge gets busier, as more and more students seek trial in its court. These are tabulated in Table 1. The verdicts are quite consistent across the board. However, the frequencies of certain types of errors appear to be language dependent. Pascal has the lowest rate of restricted function errors, reflecting its origins as a nice, safe language for students to play with. Java has had far more than its share of compiler errors to date, but it also crashes much less often than the other languages.

Safety is indeed a virtue. But the basic lesson is that the tools do not make the man. There is no finer way to debug programs than having them read by several thousand bright students, so look there for errata and revised solutions.

Instead, C encourages you to pass a pointer to any argument that you intend to modify within the body of the function. Our only use of pointers will be in parameter passing. Do not get confused between multiplication and pointer dereferencing! Higher precision ints and floats are denoted long and double, respectively. All functions return a value of type int if not otherwise specified.

No runtime checking is performed on the validity of array bounds, so such errors are a common cause of program crashes. We are not always consistent as to where the first element of each array is located.

Starting from 0 is the traditional C style. However, it is sometimes clearer or easier to start at 1, and we are willing to pay one extra memory location for the privilege. Try not to be confused when reading our code. The output of such programs is suitable to feed to other programs as input. The paradigm is one of stringing lots of little programs together rather than producing big, complicated software systems that try to do everything. This software tools philosophy has taken somewhat of a beating in recent years due to the popularity of graphical user interfaces.

Many programmers instinctively put a point-and-click interface on every program. It is easy to manipulate text output in another program, but what can you do with an image other than look at it? Figure 1. Each program must read the test data from the standard input and print the results to the standard output. Programs are not allowed to open files or to execute certain system calls. Note how your favorite language tests for the end-of-file terminating condition.

Most problems make input processing even easier by specifying a count of the number of examples or describing a special termination line. Set it up once and use it for all your entries. Java programs submitted to the judge must consist of a single source code file.

They are currently compiled and run as native applications using the gcj compiler, although this may change in the future. Note that java::io use is restricted; which implies that some features are not available. Network functions and threads are also unavailable. However, methods from math, util and other common packages are authorized. All programs must begin in a static main method in a Main class.

Do not use public classes: even Main must be non-public to avoid compile errors. However, you can add and instance as many classes as needed. Programming Hints 9 1. We assume you are familiar with such fundamental concepts as variables, conditional statements e. If you are unfamiliar with these concepts you may have picked up the wrong book, but buy it anyway for later use. It is important to realize how much power there is in what you already know. The powerful features of modern programming languages are not really necessary to build interesting things — only to do them in cleaner, better ways.

To put it another way, one becomes a good writer not by learning additional vocab- ulary words but by finding something to say. After one or two programming courses, you know all the words you need to make yourself understood. The problems in this book strive to give you something interesting to say. The bad examples all come from actual submissions to the robot judge. We find it much easier to debug our comments than our programs, and believe the additional typing is time very well spent.

Of course, with the time pressure of a contest comes a tendency to get sloppy, but do so at your own risk. You will likely be living with the program for at least a few debug cycles, and this is a modest investment in readability which you will come to appreciate. Horribly insidious errors can result from using inconsistent constants in a program. Of course, the symbolic name helps only if you actually use it in your program whenever you need the constant. However, they are often unnecessary in short programs.

In the full program, there were four blocks of three lines each moving a value to a neighboring cell. Much safer would be to write a single move-swap routine and call it with the proper arguments. This will enable you to stop execution at a given statement or condition, so you can see what the values of all associated variables are. This is usually faster and easier than typing in a bunch of print statements.

But if you are going to insert debugging print statements, make them say some- thing. Print out all relevant variables, and label the printed quantity with the variable name. Otherwise it is easy to get lost in your own debugging output. Most computer science students are now well-versed in object-oriented programming, a software engineering philosophy designed to construct reusable software components and exploit them.

Object-oriented programming is useful to build large, reusable pro- grams. However, most of the programming challenge problems in this book are designed to be solved by short, clever programs. The basic assumption of object-oriented pro- gramming just does not apply in this domain, so defining complicated new objects as opposed to using predefined objects is likely to be a waste of time. The trick to successful programming is not abandoning style, but using one appropriate to the scale of the job.

Many kinds of errors in pointer-based structures simply cannot happen with static arrays. The sign of a mature professional is keeping the simple jobs simple. This is particularly challenging for those who are just learning a new subject. Medical students provide a classic example of this problem. Likewise, you may have recently learned about balanced binary search trees, exception handling, parallel processing, and various models of object inheritance.

These are all useful and important subjects. But they are not necessarily the best way to get a correct program working for a simple job. So, yes, pointer-based structures are very powerful if you do not know the maximum size of the problem in advance, or in supporting fast search and update operations. However, many of the problems you will be solving here have maximum sizes specified. Further, the robot judge typically allows several seconds for your job to complete, which is a lot of computation time when you stop to think about it.

So what is the simple, mature approach to data structures? First, be familiar with the basic primitive data types built into your programming language. Getting Started name. They are used to store sequences of single-type elements such as integers, reals, or compound objects such as records. Arrays of characters can be used to represent text strings, while arrays of text strings can be used to represent just about anything.

Sentinels can be a useful technique to simplify array-based programming. A sentinel is a guard element, implicitly checking that the program does not run beyond the bounds of the array without performing an explicit test.

Consider the case of inserting element x into the proper position among n elements in a sorted array a. Proper use of sentinels, and making sure that your array is a little larger than it presumably needs to be, can help avoid many boundary errors. Records are important for conceptual clarity in large programs, but such fields can often be harmlessly represented using separate arrays in programs of modest size.

Whether it is better to use records or multidimensional arrays in a problem is not always a clear-cut decision. A big plus for records is that the notation p. About the Problems 13 disadvantage of the record representation is that you cannot loop over individual variables as you can elements in an array.

Suppose you wanted to change a geometric program to work with three- dimensional points instead of two, or even in arbitrary dimensions. Sure you can easily add extra fields to the record, but every place where you did calculations on x and y you now must replicate them for z. These challenges have been carefully selected from over 1, such problems collected at the Universidad de Valladolid website. We especially looked for that spark of insight which turns a problem into a challenge.

The description of each selected problem has been edited for correctness and readability. We have tried to preserve the local color and flavor of each origi- nal problem while making the language reasonably consistent. The identification number for each problem on both judging sites is provided. These numbers are important for successful submission. First, each problem has been given a grade of A, B, or C, reflecting how many correct solutions the judge has seen over the years.

A problems are presumably easier to solve or somehow more attractive than B problems. Getting Started average, or low. Low percentages may indicate particularly finicky judges, or perhaps problems that require more subtlety than is initially apparent. Or they may just reflect bugs in test cases which have since been fixed. Therefore, do not obsess too much about these ratings. Finally, we give a subjective rating from 1 to 4 of the academic level required to solve the problem.

Higher numbers indicate more sophisticated problems. Good luck, and happy hacking! Problems 15 1. Start with an integer n. If n is even, divide by 2. If n is odd, multiply by 3 and add 1. Still, the conjecture holds for all integers up to at least 1, , For an input n, the cycle-length of n is the number of numbers generated up to and including the 1.

In the example above, the cycle length of 22 is Given any two numbers i and j, you are to determine the maximum cycle length over all numbers between i and j, including both endpoints. Input The input will consist of a series of pairs of integers i and j, one pair of integers per line.

All integers will be less than 1,, and greater than 0. Output For each pair of input integers i and j, output i, j in the same order in which they appeared in the input and then the maximum cycle length for integers between and including i and j. These three numbers should be separated by one space, with all three numbers on one line and with one line of output for each line of input.

Getting Started 1. The game shows a number in a square which tells you how many mines there are adjacent to that square. Each square has at most eight adjacent squares. Each of the next n lines contains exactly m characters, representing the field. Output For each field, print the message Field x: on a line alone, where x stands for the number of the field starting from 1. There must be an empty line between field outputs. Field Problems 17 1. This spring they are planning a trip to Eindhoven.

The group agrees in advance to share expenses equally, but it is not practical to share every expense as it occurs. Thus individuals in the group pay for particular things, such as meals, hotels, taxi rides, and plane tickets. In the past, this money exchange has been tedious and time consuming. Input Standard input will contain the information for several trips.

Each trip consists of a line containing a positive integer n denoting the number of students on the trip. This is followed by n lines of input, each containing the amount spent by a student in dollars and cents. A single line containing 0 follows the information for the last trip. Sample Input 3 Before this, the most powerful machine he ever used was a pocket calculator. He is a little disappointed because he liked the LCD display of his calculator more than the screen on his new computer!

To make him happy, write a program that prints numbers in LCD display style. Input The input file contains several lines, one for each number to be displayed. The input will be terminated by a line containing two zeros, which should not be processed.

Be sure to fill all the white space occupied by the digits with blanks, including the last digit. There must be exactly one column of blanks between two digits. Output a blank line after each number. You will find an example of each digit in the sample output below.

Problems 19 1. Your task is to write a program which simulates a simple interactive graphical editor. Input The input consists of a sequence of editor commands, one per line. Each command is represented by one capital letter placed as the first character of the line. If the command needs parameters, they will be given on the same line separated by spaces. Pixel coordinates are represented by two integers, a column number between 1.

M and a row number between 1. The origin sits in the upper-left corner of the table. Colors are specified by capital letters. C Clear the table by setting all pixels white O. The size remains unchanged. Pixel X, Y belongs to R. Any other pixel which is the same color as pixel X, Y and shares a common side with any pixel in R also belongs to this region.

X Terminate the session. Each row is represented by the color contents of each pixel. See the sample output. In case of other errors, the program behavior is unpredictable.

Problems 21 1. Each register or RAM location holds a three-digit integer between 0 and Instructions are encoded as three-digit integers and stored in RAM. The encodings are as follows: means halt 2dn means set register d to n between 0 and 9 3dn means add n to register d 4dn means multiply register d by n 5ds means set register d to the value of register s 6ds means add the value of register s to register d 7ds means multiply register d by the value of register s 8da means set register d to the value in RAM whose address is in register a 9sa means set the value in RAM whose address is in register a to that of register s 0ds means goto the location in register d unless register s contains 0 All registers initially contain The initial content of the RAM is read from stan- dard input.

The first instruction to be executed is at RAM address 0. All results are reduced modulo 1, Input The input begins with a single positive integer on a line by itself indicating the number of cases, each described as below.

This is followed by a blank line, and there will be a blank line between each two consecutive inputs. Each input case consists of up to 1, three-digit unsigned integers, representing the contents of consecutive RAM locations starting at 0. Unspecified RAM locations are initialized to Output The output of each test case is a single integer: the number of instructions executed up to and including the halt instruction.

You may assume that the program does halt. Separate the output of two consecutive cases by a blank line. Problems 23 1. A king is in check if it is on square which can be taken by the opponent on his next move. White pieces will be represented by uppercase letters, and black pieces by lowercase letters. The white side will always be on the bottom of the board, with the black side always on the top. For those unfamiliar with chess, here are the movements of each piece: Pawn p or P : can only move straight ahead, one square at a time.

However, it takes pieces diagonally, and that is what concerns you in this problem. Knight n or N : has an L-shaped movement shown below. It is the only piece that can jump over other pieces. Bishop b or B : can move any number of squares diagonally, either forward or backward.

Rook r or R : can move any number of squares vertically or horizontally, either forward or backward. Queen q or Q : can move any number of squares in any direction diagonally, horizontally, or vertically either forward or backward. King k or K : can move one square at a time in any direction diagonally, horizontally, or vertically either forward or backward. Remember that the knight is the only piece that can jump over other pieces. The pawn movement will depend on its side. If it is a black pawn, it can only move one square diagonally down the board.

If it is a white pawn, it can only move one square diagonally up the board. Getting Started Input There will be an arbitrary number of board configurations in the input, each consisting of eight lines of eight characters each. There will be no invalid characters and no configurations where both kings are in check.

There will be an empty line between each pair of board configurations. All boards, except for the empty one, will contain exactly one white king and one black king. Output For each board configuration read you must output one of the following answers: Game d: white king is in check. Game d: black king is in check. Game d: no king is in check. Sample Input Sample Output.. Game 1: black king is in check. Problems 25 1. Ballots ranking these candidates first are recounted in favor of their highest-ranked non-eliminated candidate.

Input The input begins with a single positive integer on a line by itself indicating the number of cases following, each as described below. This line is followed by a blank line. There is also a blank line between two consecutive inputs.

The next n lines consist of the names of the candidates in order, each up to 80 char- acters in length and containing any printable characters. Up to 1, lines follow, each containing the contents of a ballot. Each ballot contains the numbers from 1 to n in some order. The first number indicates the candidate of first choice; the second number indicates candidate of second choice, and so on.

Output The output of each test case consists of either a single line containing the name of the winner or several lines containing the names of all candidates who are tied. The output of each two consecutive cases are separated by a blank line. Is it easier to keep separate copies of the old and new image? See Lagarias [Lag85] for an excellent mathematical survey. See [GJ79] for a thorough discussion of NP-completeness. It is an interesting project to write a simulator for the machine language of an old, obsolete, but simple computer such as the PDP See [New96, Sch97] for stories of how computer chess and checkers programs work and beat the human World Champions at their own games.

See [COM94] for an interesting discussion of the mathematics of social choice. Pick the right data representation, and your task will be easy to program.

Pick the wrong representation, and you may spend enormous amounts of time and code covering up for your lousy initial decision. In this chapter, we will review the fundamental data structures which every program- mer should be familiar with.

Many classic programming problems are based on games. We also describe the simplest way to implement these structures from scratch. These will be briefly described in Section 2. Once you do, you can read this section with an eye for what each data structure is good for instead of the details of how it should be implemented. Data Structures 2. Stacks maintain last-in, first-out order. Note that there is no element search operation defined on standard stacks and queues. Defining these abstract operations enables us build a stack module to use and reuse without knowing the details of the implementation.

The easiest implementation uses an array with an index variable to represent the top of the stack. Stacks naturally model piles of objects, such as dinner plates. After a new plate is washed, it is pushed on the top of the stack. Stack order is important in processing any properly nested structure. This appears fairer than last-in, first-out, which is why lines at stores are organized as queues instead of stacks.

FIFO queues will be used in implementing breadth-first search in graphs in Chapter 9. The simplest implementation uses an array, inserting new elements at one end and moving all remaining elements to fill the empty space created on each dequeue.

However, it is very wasteful to move all the elements on each dequeue. How can we do better? There is no reason why we must explicitly clear previously used cells, although we leave a trail of garbage behind the previously dequeued items. Circular queues let us reuse this empty space. Note that the pointer to the front of the list is always behind the back pointer! When the queue is full, the two indices will point to neighboring or identical elements. There are several possible ways to adjust the indices for circular queues.

All are tricky! But what we usually want in practice is the simplest way to get the job done under the given time constraints. Thus they need to support search, but not insertion on deletion. The right answer for static dictionaries is typically an array. The only real question is whether to keep it sorted, in order to use binary search to provide fast membership queries. Sorting algorithms and binary search always prove harder to debug than they should. If we know an upper bound on the number of elements to be inserted we can use an array, but otherwise we must use a linked structure.

Elementary Data Structures 31 Hash tables are excellent dictionary data structures, particularly if deletion need not be supported. The idea is to apply a function to the search key so we can determine where the item will appear in an array without looking at the other items. To make the table of reasonable size, we must allow for collisions, two distinct keys mapped to the same location.

The two components to hashing are 1 defining a hash function to map keys to integers in a certain range, and 2 setting up an array as big as this range, so that the hash function value can specify an index. The basic hash function converts the key to an integer, and takes the value of this integer mod the size of the hash table. Selecting a table size to be a prime number or at least avoiding obvious composite numbers like 1, is helpful to avoid trouble. The absence of deletion makes open addressing a nice, easy way to resolve collisions.

In open addressing, we use a simple rule to decide where to put a new item when the desired space is already occupied. Suppose we always put it in the next unoccupied cell. On searching for a given item, we go to the intended location and search sequentially.

If we find an empty cell before we find the item, it does not exist anywhere in the table. Deletion in an open addressing scheme is very ugly, since removing one el- ement can break a chain of insertions, making some elements inaccessible.

Here we associate a linked list with each table location, so insertion, deletion, and query reduce to the same problem in linked lists. If the hash function does a good job the m keys will be distributed uniformly in a table of size n, so each list will be short enough to search quickly.

Data Structures Priority queues are used to maintain schedules and calendars. They govern who goes next in simulations of airports, parking lots, and the like, whenever we need to schedule events according to a clock.

In a human life simulation, it may be most convenient to determine when someone will die immediately after they are born. We can then stick this date in a priority queue so as to be reminded when to bury them. Priority queues are used to schedule events in the sweep-line algorithms common to computational geometry. Typically, we use the priority queue to store the points we have not yet encountered, ordered by x-coordinate, and push the line forward one step at a time.

Score: 3. The book is suitable either as a textbook or as a supplementary book in algorithm courses. Over computational problems are covered with various algorithms to tackle them. Rather than providing students simply with the best known algorithm for a problem, this book presents various algorithms for readers to master various algorithm design paradigms.

Beginners in computer science can train their algorithm design skills via trivial algorithms on elementary problem examples. Graduate students can test their abilities to apply the algorithm design paradigms to devise an efficient algorithm for intermediate-level or challenging problems. Key Features: Dictionary of computational problems: A table of over computational problems with more than algorithms is provided. Indices and Hyperlinks: Algorithms, computational problems, equations, figures, lemmas, properties, tables, and theorems are indexed with unique identification numbers and page numbers in the printed book and hyperlinked in the e-book version.

Extensive Figures: Over figures illustrate the algorithms and describe computational problems. Comprehensive exercises: More than exercises help students to improve their algorithm design and analysis skills. The answers for most questions are available in the accompanying solution manual. The authors cover classical and advanced topics on the most important combinatorial objects: permutations, subsets, partitions, and Young tableaux, as well as all important areas of graph theory: graph construction operations, invariants, embeddings, and algorithmic graph theory.

In addition to being a research tool, Combinatorica makes discrete mathematics accessible in new and exciting ways to a wide variety of people, by encouraging computational experimentation and visualization.

The book contains no formal proofs, but enough discussion to understand and appreciate all the algorithms and theorems it contains. Programming Challenges Author : Steven S. We cannot overstress that this is a huge marketing hook. Virtually every experienced programmer today started out with some version of Basic or QuickBasic and has at some point in their career wondered how it worked.

The sheer nostalgia alone will generate sales. The idea of having QuickBasic for them to play with or let their kids play with will generate sales. This book is pitched at a level accessible to all but beginners. There's detailed analysis for each problem. Great work! Thanks a lot :. You can add careercup for interview questions.

Thank you! Added : I'm still relatively unfamiliar with interview questions. This is really all what a programmer need Great contribution, like it and love it :. Thx a lot You can add www. Hello, Thanks first of all.

Can you tell me how you would recommend it? Sorry, I don't know these sites well enough. Sorry for the late reply. I've been pretty busy recently doing 2 jobs atm. It looked great I think.

I checked out a few of the problems. I have a question: Is it being actively maintained? Guys who developed it are quite active. This list is for competitive programming for the most part I'm sorry. I do intend on including it.

I just haven't gotten around to explore this site. Thanks for the suggestion. Can you tell me a bit more about him? I actually stumbled upon his profile a while ago, and he didn't have many answers back then :P Thanks, I'll place him on the list.

You're welcome. Great effort! Thanks : I submitted on the github a request to add it there. His tutorials are really helpful. Thanks, added. Sorry, it's been busy for me recently. I'll replace the link to the website with this one : The items are significantly harder too o. Hello, Thank you. I appreciate the effort. Great effort. Thank you very much Thanks for the kind words : It's been a year since I launched this project.

Time flies! I would love to, but I have rather limited knowledge when it comes to Computational Geometry. Could add this book written in spanish to the list? This does look like a good book. Can you give us an introduction for the book? I admit that it's a little overwhelming :P That said, there are also overwhelmingly many ways you can start!

Their notebook looks awesome! I'll add that to the list when I get off work today. Would you be kind enough to share your thoughts? You're very, very welcome! Glad it's helpful for you :. I apologize for being not as responsive lately. That's interesting, because I was able to download those documents last year. It was actually one of the more accessible download locations I could manage to find.

I'll probably end up removing it, because it is a little controversial. Maybe Kaggle should be added to the list. If we include data science competitions, I think there will be a lot to be added. I think it would be better to leave those for ML resource collections. Yeah LeetCode should probably be in there :. Huge thanks! Thank you very much. Thank you so much. Very helpful for all. You did a great job. Thank you all for your efforts!

Thanks a lot. This is so helpful man. Solving Trees. I want to add a awesome Youtube Channel created by Errichto. Everything in one place. Thanks alot man!! Hi, Thank for sharing nice post. Home Network Security. Best compilation on CP resource.!! Almost all the websites that I know are there in the list highly recommended. Good job! Thanks a lot Inishan ma'am.

Just wanted to draw kind attention of this old but quite informative blog. In English In Russian. Codeforces c Copyright Mike Mirzayanov.

Desktop version, switch to mobile version. User lists. B enq. M iracle R adewoosh. Countries Cities Organizations. A collection of fantastic tutorial blog posts written by Codeforces users.

All of the good tutorials found on codeforces — Codeforces. A very complete list of competitive programming resources. A detailed syllabus on which IOI contestants will be tested. Programming Camp Syllabus. Topcoder Data Science Tutorials. A list of tutorials written by respected Topcoder members.

E-Maxx Russian , English. A tutorial website widely used and referenced in the Russian-speaking competitive programming community. Algorithms — GeeksforGeeks. A website with a large archive of nicely written articles on different topics.

A website with amazing in-depth wiki-like writeups on many topics. A great crowdsourcing platform for tutorials. Contains several training pages on its website which are designed to develop one's skills in programming solutions to difficult and varied algorithmic problems at one's own pace. Competitive Programming — Commonlounge. Short video tutorials for beginner and intermediate concepts.

An international journal focused on the research and practice of professionals who are working in the field of teaching and learning informatics to talented student. A Russian website devoted to algorithms of all sorts.

One of the most popular tutorial websites among the Taiwanese competitive programming community. Papers from the Chinese IOI training camps. Codechef's Indian Programming Camp.

Lectured by Prof. This book contains a collection of relevant data structures, algorithms, and programming tips. This book includes more than programming challenges, as well as the theory and key concepts necessary for approaching them. This book is free for download pdf. An absolutely phenomenal book. An old-time classic. Introduction to Algorithms , by Thomas H. Rivest and Clifford Stein. Also known as CLRS taken from name initials , this book is often referred to as the "bible" for algorithms and data structures.

This book revolves around techniques for designing algorithms. The book is written in more readable text. Algorithms , by Robert Sedgewick and Kevin Wayne. This book is neatly categorized, coupled with elaborate explanations and fantastic illustrations. Discrete Mathematics is closely relevant to competitive programming. Knuth, Oren Patashnik. The book offers a deeper insight into Discrete Mathematics with more emphases on number-related topics. The book does a brilliant job at bridging the gap between a physical system for scientists and engineers and an abstract system for mathematicians.

Introduction to Probability , by Charles M. Laurie Snell. This is a well-written introductory probabilities book. Codeforces is one of, if not, the most popular contest platforms out there. Topcoder has been around since Google Code Jam is certainly one of the most highly-esteemed programming competitions.

AtCoder is a new but phenomenal contest platform created by a team of highly-rated Japanese competitive programmers. CodeChef is a non-profit educational initiative of Directi. The SPOJ platform is centered around an online judge system.

Timus Online Judge is the largest Russian archive of programming problems with automatic judging system. Aizu online judge is a contest platform and problem archive hosted by The University of Aizu. HackerRank is a company that focuses on competitive programming challenges for both consumers and businesses.

POJ is an online judge with many great problems maintained by Peking University. Project Euler features a stunning set of good math problems. HackerEarth is a startup technology company based in Bangalore, India that provides recruitment solutions.

New in the competitive programming scene, CS Academy is a growing online judge that hosts competitions once every two weeks. Programming competitions powered by Mail. CodeFights is a website for competitive programming practice and interview preparation. UVa Online Judge. Coding Calendar Android App. For quick answers, Codeforces is definitely the go-to place to ask about anything competition-related.

Competitive Programming — Quora. You would typically get more elaborate answers on Quora, but you might not have your questions answered straightaway. A notebook with some advanced data structures and algorithms including some from the China informatics scene. A good notebook by Igor Naverniouk who is currently a software engineer at Google and part of the Google Code Jam team. How to read input in Java — tutorial — Codeforces.

Learn how to read input faster. This is a must-read for those who intend to use Java for competitive programming. A Java library for contests written by Alexey Dergunov dalex. Everything you need to know about floating point numbers. Vim is one of the most popular text editors among advanced programmers. Emacs is another popular text editor or development environment to be more precise. Sublime Text is an extraordinary text editor.

Eclipse is another good IDE for Java. A website featuring a large collection of visualization tools for algorithms and data structures.

General Practice Helpers Great tools that parse contests, inline library codes and provide testing frameworks. Codeforces Parsers A stunning encyclopedia with a database of countless integer sequences.

Syntax Highlighters Very handy for creating slides or team notebooks with pretty, formatted code snippets.