Trying to find an example of the “walking a thin line” idiom is easy. Think of HR managers who have to align company goals and employee satisfaction!

HR leaders no longer just stick to legal and compliance issues; they are now strategic business partners with a key role to play in shaping the company’s culture and taking the company closer to realizing its vision.

The talent management and performance review processes are certainly not what we’d refer to as all in a day’s work. To add to their cup of woes, they have “mundane” tasks—finding top quality hires, retaining them, ensuring there are no pains areas in employee engagement, staving off all kinds of legal hassles—which require them to be the go-to person while being innovative, proactive, and brimming with energy.

Apparently, this is possible.

Thanks to the digital era, the market is now flooded with tools, apps, and processes to help HR pros kick back and relax. For instance, HR innovation was the theme of the successful “Hack the Experience” hackathon sponsored by Brilliant Ink. The event held in San Francisco in 2014 drew over100 professionals collaborated to come up with solutions to improve employee engagement.

Hackathons—an underrated tool

Hackathons can give you the vision. You can create employee experiences that are compelling and fun. These high-energy events are much more than people working collaboratively on a brilliant idea using software and hardware to solve a problem. Let’s see how.

80% of Fortune 100 companies use hackathons to drive innovation. You too can! Learn how

Expect the unexpected

Who hasn’t been guilty of failing to recognize talent right under the nose? It happens.

You can fix this. Conduct an internal hackathon to assess your company’s existing employee pool. You will be amazed at the “hacks” your employees can come up with.

Tech companies benefit greatly from holding hackathons for its developers where they have to think outside the box and prove their mettle under time and problem constraints.

“It can also provide good clues on design sensibilities, presentation skills and team collaboration ability of the engineer,” says Ravi Gururaj, chairman of the Nasscom Product Council.

And how right he is.

HR managers should advise team leads to gauge the competency of their team members before putting in requests for urgent hires.

“If you’re inside a company and convinced you have the best thing and if only you could get visibility in front of your CTO—then an internal hackathon is a great way of enticing the internal developers to skip to the top of the list, get an exclusive peak of data or even incubation,” says Delyn Simmons from Mashery.

People can get all fired-up when they realize they aren’t going to be putting the company at risk by implementing avant-garde ideas in their everyday projects. At an internal hackathon, employees are encouraged to come up with actionable solutions. Give them a carte blanche.

Like Sabeen Ali, founder of AngelHack, says, “They (employees) get to lower their typical boundaries, typical restriction, and build something that they think isn’t part of their immediate role or immediate responsibility. There’s a freedom to it.”

It is a chance for you to tap into potential talent without having to spend time and money looking for skills outside the organization. Say goodbye to a pile of résumés, and say hello to some vacation days.

Get your company to adopt it as a business practice.

Wipro held an internal hackathon for its employees in June 2014.

Wipro CEO T K Kurien said, “We intend to do one hackathon every month. You realize people’s competency once you go through a hackathon. You find that competency sometimes doesn’t reside at the top of the pyramid; it lies right at the bottom.”

Be ready for unprecedented employee engagement

You want engaged employees, people who are passionate about their work and enjoy a sense of belonging in the company. Engaged employees believe in innovation and helping the organization go forward. The not-so-engaged employees will go through motions, but they won’t do much more. The actively disengaged employees undermine team accomplishments, showing their unhappiness every chance they get. Gallup says that businesses in the U.S. lose $350 billion every year because of disengaged employees!

HR managers can unleash the phenomenal power of engaged workers by ensuring employee commitment, making them go the extra mile for the company only because they want to. They can use hackathons as tools to bring about meaningful change. Through hackathons, HR leaders drive engagement by focusing on self-directed and dynamic learning, a diverse and flexible work environment, encouraging empowered teams and transparency and honesty by the management, facilitating talent mobility, and ensuring a culture of recognition.

Using tools such as hackathons, HR can help build camaraderie and cohesiveness. Along with getting rid of organizational silos and fostering innovation, such hackathons set the scene for employee recognition and other employee-focused initiatives such as enhancing employee engagement for better productivity and overall profitability.

Pi Wen Looi, the president of Novacrea, a California-based business management consulting firm, and the head judge of “Hack the Experience,”said, “Employee engagement is a complex problem. There’s more than one thing that feeds into whether or not a person is engaged. A hackathon like this gets a lot of people thinking about the problem in different ways. You’re kind of attacking it from different angles.”

Companies such as LinkedIn and Facebook are also using hackathons to tackle low levels of employee engagement. In the LinkedIn HR hackathons, “interns with diverse backgrounds, experiences, and disciplines” from the Silicon Valley compete to come up with innovative solutions to help HR execute its priorities successfully.

So, what’s stopping you from doing one for your company? Disrupt HR!

You could take a leaf out of CISCO’s notebook and reconfigure the HR function.

Build innovative tangible products

In the hackathon lingo, the word innovation is perhaps the most hackneyed. But there really isn’t another term that quite crystallizes what these events embody. Here are a few examples of what the coming together of enthusiastic minds can achieve. Products may not be fully fleshed out but the promise they hold is immense.

At HackerEarth internal hackathons have become de rigeur to break everyday monotony and unlock excellence. Held every quarter, the company had 10 so far. Five ideas shortlisted from every hackathon go into production. Over 50 products have been rolled out, either to customers or internal teams. Code Monk, Wordsworth, Flash, and Optimus. No, they aren’t names of Transformers! These are some of the wildly successful products HackerEarth’s teams created at internal hackathons. Code Monk is an app for learning programming on the go; it’s been downloaded 88,000 times in six months. Wordsworth is an internal grammar and guideline checking tool. Flash is a caching system that decreases the page load time, thereby enhancing customer experience and improving page ranking. BlackOps is an in-house mail engine which saves more than $3500 per annum, and Optimus is a bot which monitors, reports, and resolves issues in the infrastructure saving us countless man hours. What you need to know is that none of these tools were a part of the plan or roadmap. They wouldn’t have come about without internal hackathons.

Madhusudhan Anand, Engineering Manager at HackerEarth, said, “The coming together of teams boosts morale when everyone ideates together to solve a problem and having fun while doing so greatly improves engagement. Then the camaraderie that comes from people working across different parts of the organization has always been a great way to strengthen communication and foster a sense of collaboration, community, and innovation that comes with being a part of the HackerEarth Family.”

Watch your company culture get upvoted

As an HR manager, if you can’t come up with ideas to boost the sagging spirits, why not ask the employees to identify ways to address the pain points? At Big Spaceship, the overnight hackathon Hack the Spaceship was about finding creative ways to improve company culture.

You can teach the employees what the company is about.

One of the best examples of reinforcing company values through internal hackathons is by doing what Atlassian, a Sydney-based enterprise software company, does. The employees wait for the ShipIt days. The challenge embodies the company’s values: be the change you seek, play as a team, and build with heart and balance. People don’t take them too seriously or get too competitive. They have 24 hours of fun, enjoying fantastic interdepartmental collaboration, and reaping rewards of many kinds.

You only need look at what Facebook’s hackathons did for its culture.

In Pedram Keyani’s words: Hackathons organically encourage culture-building and collaboration within the company without any top-down guidance. Employees, both new and old, work together quickly and efficiently, improvising and brainstorming, failing and winning, and achieving new levels of interpersonal harmony.

At hackathons, employees are likely to make a couple of lasting friendships, and they come to depend on each other in positive ways. The chances these employees will recommend the company to people outside are quite high.

Talent retention becomes easier; disgruntled employees become fewer.

Hiring becomes the easiest part of the job

If you are talking external hackathons, then HR managers responsible for recruitment already know what this is about.

Finding game changers within the organization could happen with internal hackathons. But if it doesn’t, then you need to look elsewhere. As an HR manager, you can get the management to host or attend hackathons to capture the right talent.

Community building and entrepreneurship are not the only focus areas of hackathons now. They are routinely used to recruit people with the right skills and attitudes.

HR can network with the organizers to get access to interesting profiles. When you attend events, building rapport can’t hurt. Understand what the hackathons are about, and find out why the participants are attending them.

Scout for tech talent at relevant hackathons, and you’ll meet your target before you know it.

Don’t wait for the flip side. There isn’t one.

People love to hate HR, but you don’t need to give them reasons.

HR doesn’t have to be the bearer of bad tidings always. And there are enough hours in a workday to get everything done.

You can do more than “slapping bandages on problems.”

Getting people strategies and business needs to be looking at the same end goals requires more than a little nudge in the right direction.

Whether you are tasked with protecting company culture, getting the brightest minds, retaining talent, or upping employee engagement rates this quarter, there’s help.

You just need to look in the right places.

Looking to conduct online coding tests to hire developers for your organization? Try HackerEarth Recruit free for 14 days to start creating tests for your candidates right away.

How does alpha-beta pruning work?

1. Initialize alpha = -infinity and beta = infinity as the worst possible cases. The condition to prune a node is when alpha becomes greater than or equal to beta.
2. Start with assigning the initial values of alpha and beta to root and since alpha is less than beta we don’t prune it.
3. Carry these values of alpha and beta to the child node on the left. And now from the utility value of the terminal state, we will update the values of alpha and be, so we don’t have to update the value of beta. Again, we don’t prune because the condition remains the same. Similarly, the third child node also. And then backtracking to the root we set alpha=3 because that is the minimum value that alpha can have.
   
4. Now, alpha=3 and beta=infinity at the root. So, we don’t prune. Carrying this to the center node, and calculating MIN{2, infinity}, we get alpha=3 and beta=2.
5. Prune the second and third child nodes because alpha is now greater than beta.
6. Alpha at the root remains 3 because it is greater than 2. Carrying this to the rightmost child node, evaluate MIN{infinity,2}=2. Update beta to 2 and alpha remains 3.
7. Prune the second and third child nodes because alpha is now greater than beta.
8. Hence, we get 3, 2, 2 at the left, center, and right MIN nodes, respectively. And calculating MAX{3,2,2}, we get 3. Therefore, without even looking at four leaves we could correctly find the minimax decision.

evaluate (node, alpha, beta)

     if node is a leaf

        return the utility value of node

     if node is a minimizing node

        for each child of node

            beta = min (beta, evaluate (child, alpha, beta))

            if beta <= alpha

                return beta

            return beta

     if node is a maximizing node

        for each child of node

            alpha = max (alpha, evaluate (child, alpha, beta))

            if beta <= alpha

                return alpha

            return alpha

Conclusion

Perhaps a post on these programming languages needs no fore ward. But then again, for the skeptics who are rooting for Go and Swift, here’s a little bit of background that reinforces the fact that despite not being the most popular ones today, these object-oriented languages still form the base for many applications.

Why bother

Java and C# were touted as the pet languages of the 2000s. Now, people talk Python and Ruby, Javascript and PHP.However, fundamental programming skills still necessitate a solid foundation in C and C++. (You can read more here- Top programming languages that will be most popular in 2017)

TIOBE may be scorning C now, but Dice and other job portals show a significant demand for these skill sets across industries. Beginner-friendliness, scalability, and a sizable community continue to make C++ a major player as well.

“They [C and C++] are the native tongue for system-level programming, and they probably will be for many years. Eventually, though, languages like Google Go or D may replace them,” says Gartner Research Analysts Mark Driver. “The trial-by-fire of learning C tends to weed out the noncommitted, so knowledge of C at the very least makes you stand out,” he added.

These languages act like a “mental model” that helps you go where places you thought you couldn’t. Bjarne Stroustrup, the C++ creator, says, “Basically, nothing that can handle complexity runs as fast as C++.” Used with some scripting language, it is for “high performance, high reliability, small footprint, low energy consumption, all of these good things.”

With a plethora of resources available, choosing the best can leave you in a tizzy. We’ve got a list, a valuable one, which keeps the curious ones who wonder what’s beneath the hood get as “close to the machine” as possible.

Stroustrup: The C++ Programming Language (4th Edition)

What’s better than studying from the guru himself? Bjarne Stroustrup created C++ in 1979.

The book covers the language in its entirety, talking about containers, algorithms, abstraction mechanisms, concurrency, utilities, basic facilities, standard libraries, and design models. This reorganized edition discusses C++11, a version that followed C++03, and then got superseded by C++14 and C++17 later on. A must-have for programming enthusiasts, because it certainly is a definitive reference book for general programming principles and practice using C++. Reviewers are raving about the code examples and the way the language has been presented. It may not be the best book for novices according to some readers; it is more of a “description of the features and the reasoning” than answering how-tos. Look at the detailed table of contents here and access the exercises here.

You can buy the book here.

Accelerated C++: Practical Programming by Example by Andrew Koenig and Barbara E. Moo

For learners who are eager to get into the practical aspects of C++, this book, which is a part of Stroustrup’s C++ in-depth series, is the go-to reference. If you don’t have time for the basics, then you can go directly into the coding bit with the help of Koenig and Moo’s “accelerated” C++. Topics covered include “basic string handling, loop and flow-control statements, arrays, functions and methods, iterators, file I/O, operator overloading, inheritance, polymorphism and virtual functions.”

Founding member of the ANSI/ISO C++ committee, Dag Brück, says “This is a first-rate introductory book that takes a practical approach to solving problems using C++. It covers a much wider scope of C++ programming than other introductory books I’ve seen, and in a surprisingly compact format.” The authors talk about features using understandable examples, teaching you how to use the features rather than trying to explain the whats and whys. It takes you from standard library abstractions to defining your own. Key takeaways that crystallize low-level and high-level concepts and end-of-chapter exercises cement your understanding.

With this book, you can begin programming right away!

You can buy the book here.

C++ Primer (5th Edition) 5th Edition by Stanley B. Lippman, Josée Lajoie, and Barbara E. Moo

In the C++ primer, the authors focus on the 2011 revised standard. In the Why Read This Book section, they say they “emphasize good style and explain the rationale behind the rules.” The first part of the book covers basics of C++ such as variables, strings, vectors, arrays, expressions, statements, functions, and classes. The next section deals with the I/O library, sequential and associative containers, generic algorithms, and dynamic memory. Another part takes you through copy control, overloaded operations and conversions, OOP, templates, and generic programming. The primer teaches you high-level programming techniques, such as specialized library facilities and tools for large programs, in the later sections. Learners don’t have to know C, but they need to be familiar with writing, compiling, and running a program “in at least one modern block-structured language.”

You can buy the book here.

Effective Modern C++: 42 Specific Ways to Improve Your Use of C++11 and C++14 (1st Edition) by Scott Meyers

A part of his Effective C++ book series, this edition talks about how you can use the new features of C++11 and C++14, such as lambda expressions and move semantics, effectively. A software architect at Microsoft and chair of ISO C++ standards committee, Herb Sutter, says: “After I learned the C++ basics, I then learned how to use C++ in production code from Meyer’s series of Effective C++ books. Effective Modern C++ is the most important how-to book for advice on key guidelines, styles, and idioms to use modern C++ effectively and well. Don’t own it yet? Buy this one. Now.”

With this book, Meyers ensures that you can “create software that’s correct, efficient, maintainable, and portable.” Topics covered include perfect forwarding, except specifications, braced initialization, auto type declarations, and differences between std:: atomic and volatile and their relation to the concurrency API of C++.

A few reviewers feel that some basic knowledge of C++ is required to fully appreciate this edition on modern C++. Lots of great examples and bite-sized “items” tell you why the features have been added and what they can do; it is a set of guidelines on the newer additions to C++ rather than an introductory text to learn C++.

You can buy the book here.

Exceptional C++: 40 New Engineering Puzzles, Programming Problems, and Solutions by Herb Sutter

This top-quality book is a part of Stroustrup’s C++ in-depth series. Written by Herb Sutter, arenowned expert in C++, the book talks about the what, the why, and the how-to of “solid software engineering” using scenarios in a problem-solution format. Sutter answers questions such as “How does writing inline affect performance? How does exception safety go beyond try and catch statements? What’s the real memory cost of using standard containers?”

If you want to be one of the best C++ programmers around, Exceptional C++ is a definitive guide to topics such as generic programming, writing reusable templates, exception safety issues, compiler firewalls, class design, inheritance, and polymorphism, and optimization. Exemplary presentation and entertaining puzzles make this a must-buy. His next book, More Exceptional C++: 40 New Engineering Puzzles, Programming Problems, and Solutions continues the journey. With an aim to help you write exceptional code, the book comes with new detailed sections (e.g. multi-threaded environments) and insights on vital topics covered in the prequel.

You can buy the book here.

The C Programming Language 2nd Edition by Brian W. Kernighan and Dennis M. Ritchie

Despite having been originally published in 1978, this amazing book continues to be the bible for C programmers. Ritchie (1941–2011) was the original C language designer, and he also co-designed the UNIX OS. The K&R (authors) C version is different from the ANSI C or the earlier version.

The book discusses has challenging exercises to help you attain a working knowledge of C. It concisely and clearly types, operators, and expressions, control flow, functions and program structure, pointers and arrays, structures, input and output, and the UNIX system interface. You need some programming background; you need to know what a compiler is; the book teaches you the syntax and not exactly the programming principles. For example, when it talks four pages about functions, it doesn’t actually tell you what a function is. Still, this seminal text has the first Hello World program.

In the preface to the second edition published in 1988, the authors write: We have improved the exposition of critical features, such as pointers, that are central to C programming. We have refined the original examples, and have added new examples in several chapters. For instance, the treatment of complicated declarations is augmented by programs that convert declarations into words and vice versa. As before, all examples have been tested directly from the text, which is in machine-readable form.

You can buy the book here.

A Book on C: Programming in C (4th Edition) by Al Kelley and Ira Pohl

Kelley and Pohl have put together a great tutorial on ANSI C. The authors have used unique and clear explanations of program code, along with all-encompassing exercises and summary tables, to highlight the power of C, a general purpose programming language.

The USPs of the book include a chapter on how to move to Java from C, detailed coverage of pointers, multi-file programming, and recursion, an improved standard library functions appendix, and more focus on abstract data types. The comprehensive tutorial on ANSI C also discusses input/output and the operating system, lexical elements, operators, and the c system, the preprocessor, structures, functions, unions, transitioning to C++ from C, how ANSI C is different from traditional C, and advanced applications.

You can buy the book here.

Expert C Programming: Deep C Secrets by Peter van der Linden

This book isn’t for a beginner either. Once you have learned C from K & R, Linden’s book can answer questions such as “How can you debug linker errors? What is an activation record? Why are arrays and pointers not identical?” Unlike most bland technical books, Linden has managed to keep the reader engaged with humor, puzzles, depth of content, cultural references, and exercises. Although some bits in the book may not seem relevant anymore, it is still a satisfying read with its hacker stories and more.

John Barry, the author of Sunburst, Technobabble, and other books says “In Expert C Programming, Peter van der Linden combines C language expertise and a subtle sense of humor to deliver a C programming book that stands out from the pack. In a genre too often known for windy, lifeless prose, van der Linden’s crisp language, tongue-in-cheek attitude, and real-world examples engage and instruct.”

For C programming enthusiasts, this book is about the background stories and the appreciation for the language. The lore aside, Linden discusses advanced concepts related to compiling, pointers, and memory usage. The 11 chapters have positive titles that make you curious about linking, runtime data structures, declarations, arrays, and so on.

You can buy the book here.

Let us C by Yashavant P. Kanetkar

This is a book that helps you learn C from scratch. The author, who says he picked up the language from Dennis Ritchie’s book on C programming, has explained the basic concepts such as decision control instruction, complex decision making, loop control instruction, complex repetitions, case-control instruction, functions, pointers, recursion, data types revisited, the c preprocessor, arrays, strings, structures, console input/ output and file input/ output, C in Linux, and operations on bits in an easy-to-understand format. The book also teaches you how to create programs using Visual Studio and NetBeans.

You can buy it here.

Introduction to Algorithms 3rd Edition by Thomas H. Cormen, Charles E. Leiserson, Ronald L. Rivest, and Clifford Stein

This is what Daniel Spielman, Henry Ford II Professor of Computer Science, Mathematics, and Applied Science at Yale, has to say about this book, “Introduction to Algorithms, the ‘bible’ of the field, is a comprehensive textbook covering the full spectrum of modern algorithms: from the fastest algorithms and data structures to polynomial-time algorithms for seemingly intractable problems, from classical algorithms in graph theory to special algorithms for string matching, computational geometry, and number theory. The revised third edition notably adds a chapter on van Emde Boas trees, one of the most useful data structures, and on multithreaded algorithms, a topic of increasing importance.”

The book is meant for readers at all levels. With a bit of programming background, learners can grasp the magic—design, and analysis—of algorithms. The book broadly covers foundations, sorting and order statistics, data structures, advanced techniques such as dynamic programming and greedy algorithms, advanced data structures such as Fibonacci Heaps and van Emde Boas Trees, graph algorithms, and a few selected topics such as matrix operators, linear programming, polynomials and FFT, string matching, computational geometry, and NP-completeness.

You can buy the book here.

Data Structures and Algorithms Made Easy by Narasimha Karumanchi

For whom is this book? Prof. Hsin-Mu Tsai, National Taiwan University, answers it in his book review. He says, “This book is a good supplement to a conventional data structure textbook, as it offers many good code examples and selections of relevant problems **with solutions**. There is no deep analysis or detailed proof in this book, which is not what this book is for (for example, as a textbook to teach algorithm and complexity analysis), and what you would be able to find in a conventional data structure textbook. The book could also be good for a professional who just wants a quick review of important data structure concepts and implementations.”

Reviewers on Amazon believe that this book is a must-have for job interviews and competitive exams. The author emphasizes problem analysis over theory. The book is coded in C and C++. A comprehensive introduction, recursion and backtracking, linked lists, stacks, queues, trees, heaps, graph algorithms, sorting, searching, selection algorithms, symbol tables, hashing, string, divide-and-conquer, and greedy algorithms, complexity classes, and dynamic programming are the key chapters in the book. Looks like he has covered just about everything you need for a binge-reading evening!

You can buy the book here.

Summary

Computers are not about calculations, they are about information—organizing, retrieving, and manipulating it. You want to write efficient programs? Then you need to understand and learn to work with data structures. Data structures and algorithms tell you how you can put the programming languages you mastered to good use. Pick up C and C++ and implement and play around with data structures, and see how exciting it all is. In spite of young upstarts, dependable C and C++ continue to be the programming languages of choice for several applications.

• Nodejs - To create the API server and the mock sensor data generator
• Kafka - To build the data pipeline
• Apache Spark - To process the real-time data stream and generate metrics to measure the driving quality
• ReactJs - To create the dashboard web app
• Google roads & maps API : To get the traffic and ETA data

1. The Android app: Simulated by the team, this app aggregates locally and sends the chunks of sensor data to the API server via an HTTP endpoint.
2. API Server: This matches the data with the schema and if valid, it puts the data in Kafka queue.
3. Engine: Made with the Apache Spark, this helps sensor data to aggregate and form metrics such as sharp acceleration, hard braking, sharp turns, etc. These metrics, in turn, are used to generate a dynamic driving quality score for the driver. This score forms the basis of a lot of analytics and functionalities that this system provides.
4. Dashboard: The dashboard provides a beautiful and intuitive interface to take proactive decisions as well as run analytics using the provided APIs. It has been written using ReactJS.

• A dynamic profile and the dashboard of the rider describing his driving style, which affects his rating.
• An actionable "real-time" rash driving reporting system which allows the authorities and the hub incharges to react before it’s too late.
• A dashboard usable by both the fleet managers and traffic police control board to visualise the data such as incident distribution by time, which tells at what time of the day a driver is more likely to drive in an unsafe manner.
• A modular system in which the new data sources, metrics, and models can be added so that the third-party vendors can be easily on-boarded onto the platform.

1. Setting up the entire system architecture with different components by developing them in isolation and then combining them together to work seamlessly
2. Deciding the thresholds for different metrics after which the driving will be considered rash
3. Creating a linear predictor for the driving quality score vs time with only one data point
4. Creating a synthetic feature as generating the score itself is challenging enough

1. Create and SDK for easy data collection and integration with different apps and make it possible for third-party vendors to utilise this data
2. Improve the driving score model to include even more parameters and make it more real-world oriented
3. Create a social profile which lets the users share their driving score
4. Enable enterprise grade plug-n-play integration support

Now that we have looked at an example of the functionality of Apriori Algorithm, let us formulate the general process.

General Process of the Apriori algorithm

The entire algorithm can be divided into two steps:

Step 1: Apply minimum support to find all the frequent sets with k items in a database.

Step 2: Use the self-join rule to find the frequent sets with k+1 items with the help of frequent k-itemsets. Repeat this process from k=1 to the point when we are unable to apply the self-join rule.

This approach of extending a frequent itemset one at a time is called the “bottom up” approach.

Mining Association Rules

Till now, we have looked at the Apriori algorithm with respect to frequent itemset generation. There is another task for which we can use this algorithm, i.e., finding association rules efficiently.

For finding association rules, we need to find all rules having support greater than the threshold support and confidence greater than the threshold confidence.

But, how do we find these? One possible way is brute force, i.e., to list all the possible association rules and calculate the support and confidence for each rule. Then eliminate the rules that fail the threshold support and confidence. But it is computationally very heavy and prohibitive as the number of all the possible association rules increase exponentially with the number of items.

Given there are n items in the set [latex]I[/latex], the total number of possible association rules is [latex]3^n - 2^{n+1} + 1[/latex].

We can also use another way, which is called the two-step approach, to find the efficient association rules.

The two-step approach is:

Step 1: Frequent itemset generation: Find all itemsets for which the support is greater than the threshold support following the process we have already seen earlier in this article.

Step 2: Rule generation: Create rules from each frequent itemset using the binary partition of frequent itemsets and look for the ones with high confidence. These rules are called candidate rules.

Let us look at our previous example to get an efficient association rule. We found that OPB was the frequent itemset. So for this problem, step 1 is already done. So, let’ see step 2. All the possible rules using OPB are:

Pros of the Apriori algorithm

1. It is an easy-to-implement and easy-to-understand algorithm.
2. It can be used on large itemsets.

Cons of the Apriori Algorithm

1. Sometimes, it may need to find a large number of candidate rules which can be computationally expensive.
2. Calculating support is also expensive because it has to go through the entire database.

R implementation

The package which is used to implement the Apriori algorithm in R is called arules. The function that we will demonstrate here which can be used for mining association rules is

apriori(data, parameter = NULL)

The arguments of the function apriori are

data: The data structure which can be coerced into transactions (e.g., a binary matrix or data.frame).

parameter: It is a named list containing the threshold values for support and confidence. The default value of this argument is a list of minimum support of 0.1, minimum confidence of 0.8, maximum of 10 items (maxlen), and a maximal time for subset checking of 5 seconds (maxtime).

Summary

1. How to hire a data scientist
2. 5 must-have proctoring tips for a developer assessment platform
3. How to ensure your tech talent pool is poaching proof