Mastering Algorithms and Data Structures: Key to Enhancing Problem-Solving Skills and Algorithmic Thinking

MahdiehMortazavi
19 min readAug 7, 2024

--

Algorithmic thinking, algorithm, data structure, problem solving

Ready to dive deeper into the fascinating world of algorithms? Before we explore the specialized topics in our series on algorithms, it’s crucial to understand algorithmic thinking. In our previous article “Basic Foundations of Programming”, we covered the basic concepts of algorithms and data structures. Now, let’s take a step further and focus on how to think algorithmically. This approach involves solving problems in a systematic and logical way, using principles of iteration and optimization. By mastering “Algorithmic Thinking”, we can break down complex problems into simpler, more manageable steps, leading to more efficient and effective solutions. Gaining this understanding will better prepare us for the advanced topics in algorithms and data structures that we will explore next.

1.Abstract

In today’s advanced world, information and communication technology has become one of the fundamental pillars of daily life. Programming and software development play key roles in improving efficiency and productivity across various fields, from industry and commerce to education and public services. Among these, concepts such as algorithms and data structures — main foundations of computer science — gain special importance. These concepts not only improve software performance but also enhance the problem-solving skills and logical thinking of programmers.

The primary objective of this article is to provide a comprehensive and practical perspective on the significance and applications of algorithms and data structures, the challenges associated with learning them, and strategies for improving these skills. This article delves into a thorough examination of the importance of algorithms and data structures in programming and software development. Initially, it highlights the crucial role these concepts play in enhancing the efficiency and scalability of programs, improving problem-solving and coding skills, and underscores the necessity of mastering these concepts to grasp more advanced topics in computer science such as machine learning and data science. Additionally, it explores the impact of algorithms on everyday life and their influence on various aspects of our daily activities.

The discussion proceeds to address the challenges encountered in learning and implementing algorithms and data structures. Issues such as poor design, inappropriate selection of data structures, and implementation difficulties are scrutinized, with solutions to overcome these challenges being proposed. Furthermore, common misconceptions about algorithm complexity and the importance of persistence in learning are discussed.

One of the key sections of this article is the explanation of algorithmic thinking and its significance in solving coding problems. Algorithmic thinking represents a cognitive shift that aids programmers in systematically and logically approaching problems, rather than relying on shortcuts and unwritten rules, thereby enabling them to devise optimal solutions.

2. The Crucial Role of Algorithms and Data Structures

Programming languages are fundamental tools for writing software. They have specific rules and instructions that allow programmers to express their ideas and logic in a way that a computer can execute. Familiarity with these languages enables us to write correct code, handle compile-time and runtime errors, and produce reliable software. Data structures and algorithms are fundamental concepts in computer science that play a crucial role in programming and software development. Data structures are designed to organize and store data efficiently so that operations can be performed effectively. Algorithms are step-by-step methods or formulas for solving specific problems. These concepts help improve efficiency, optimize resource use, ensure scalability, facilitate systematic problem-solving, and succeed in job interviews.

3. Why Learning Data Structures and Algorithms (DSA) is Essential

Programming languages are essential tools for writing software. They have specific rules and commands that enable programmers to express their ideas and logic in a way that a computer can execute. Familiarity with these languages allows us to write code correctly, handle compilation and runtime errors, and produce reliable software. Data structures and algorithms are fundamental concepts in computer science and play a crucial role in programming and software development. Data structures are designed to organize and store data efficiently, while algorithms are step-by-step methods or formulas for solving specific problems. Mastery of these concepts enhances efficiency, optimizes resource usage, ensures scalability, facilitates systematic problem-solving, and improves performance in job interviews.

Here are the reasons why learning algorithms and data structures (Data Structures and Algorithms — DSA) is essential:

Enhancing Problem-Solving Skills: Learning DSA allows the development of a systematic approach to problem-solving applicable to a wide range of situations in computer science. When faced with a complex problem, the ability to think logically and analyze precisely to find an appropriate solution is critical.

Improving Coding Efficiency: Understanding how to use appropriate data structures and algorithms enables quick and high-performance coding. For example, various sorting algorithms can reduce program execution time and optimally organize data.

Facilitating the Learning of New Computer Science Concepts: Many advanced concepts in computer science are built on the principles of data structures and algorithms. A deep understanding of these concepts and a strong foundation in DSA allow for easy mastery of newer and more complex topics like machine learning, data science, system design, and more.

Enhancing Career Success: Many employers highly value DSA skills. A strong understanding of these concepts demonstrates the ability to create intelligent solutions for complex problems, which is often a key requirement in technical job roles.

Increasing Flexibility and Scalability: With a foundational knowledge of data structures and algorithms, flexible and scalable systems can be designed, easily adapting to new needs and future changes.

Promoting System Stability and Reliability: Using appropriate data structures and algorithms enhances the stability and reliability of software systems. Optimal data structures and algorithms can prevent errors arising from improper data management and ensure the system’s efficiency under various conditions.

By mastering data structures and algorithms, programmers can significantly enhance their problem-solving abilities, coding efficiency, and overall effectiveness in software development and computer science.

4. The Ubiquity of Algorithms in Daily Life

Beyond the significant topics discussed regarding the importance of Data Structures and Algorithms (DSA), it is essential to recognize that algorithms are extensively present in our daily lives. We can observe algorithmic logic in natural patterns and everyday activities such as sorting, scheduling, counting, and optimizing. Sometimes, this simple and concise logic helps us perform tasks effectively. In his book “The Formula: How Algorithms Solve All Our Problems and Create More,” Luke Dormehl delves into the role and impact of algorithms in everyday life.

Dormehl’s book examines the influence of algorithms on human life in the modern era. He defines the term “formula” as a set of actions through which resources are used to achieve value. Dormehl demonstrates that data-driven processes determine who we are and that personal relationships are also shaped by algorithms. He expresses concerns about the impact of automation on the rule of law and the future of human art and creativity. Dormehl emphasizes that algorithms shape human identity and decision-making, creating challenges in maintaining individual autonomy and social control. He encourages us to reflect on the meaning of being human in the age of algorithms and to examine the crisis of individual identity.

4.1. Key Points from Dormehl’s Analysis:

  1. Algorithmic Logic in Daily Activities: Algorithms simplify various everyday tasks such as sorting items, scheduling activities, counting objects, and optimizing processes, making our lives more efficient.
  2. Impact on Personal Identity: Data-driven processes influence our identities, determining our preferences, behaviors, and personal relationships.
  3. Influence on Decision-Making: Algorithms play a significant role in human decision-making, affecting choices in various aspects of life.
  4. Concerns about Automation: The book highlights concerns about how automation might affect the rule of law, creativity, and artistic expression, raising questions about the future of these human endeavors.
  5. Social and Individual Challenges: Dormehl discusses the challenges posed by algorithms in maintaining personal autonomy and social control, suggesting that these technologies could lead to a crisis in individual identity.
  6. Reflection on Humanity: The book invites readers to reflect on what it means to be human in an age dominated by algorithms, urging a deeper consideration of the impact of these technologies on human life.

In conclusion, algorithms are not just technical tools but are deeply embedded in our daily lives, influencing how we interact with the world and shaping our identities and decisions. The insights from “The Formula” underscore the need to understand and critically evaluate the role of algorithms to navigate the complexities of modern life while preserving human values and autonomy.

5. Challenges in Learning DSA

In the previous section, we discussed the importance and necessity of learning algorithms and data structures. Now, we will address the causes of weaknesses in implementing data structures and algorithms, and after understanding them, discuss the role of individuals in these causes and solutions to overcome them.

5.1. Key Challenges and Solutions

Challenges in Learning Data Structures and Algorithms
Table 1. Challenges in Learning Data Structures and Algorithms

5.2. Strategies for Overcoming Challenges in Learning and Implementing Algorithms and Data Structures

Given these reasons, understanding the role of individuals in these factors and striving to address them can lead to the design and implementation of more efficient and effective algorithms and data structures. Effective strategies for eliminating or controlling the role of individuals in poor algorithm implementation are presented in Table 1, followed by an explanation of each.

  • Correcting misconceptions about programming algorithms: One common misconception is that programming algorithms are exceedingly complex and difficult to master. This belief can deter beginners from engaging with this important topic. To dispel this misconception, it is essential to highlight the practical applications of algorithms and understand that these concepts can be learned through continuous practice and review.
  • Continuous learning: Mastery in data structures and algorithms requires persistent practice. Neglecting practice for extended periods can affect comprehension and problem-solving abilities. Resuming practice often means starting over, so it is important to maintain a consistent learning schedule that includes various activities such as self-study, review, problem-solving on paper, coding practice, discussions, clarifications, and mock interviews. Using platforms like LeetCode, even solving one question daily can be beneficial. Over a month, solving 30 questions is a significant achievement, and gradually, one can handle medium to hard questions as skills develop.
  • Understanding interdependencies of topics: DSA topics are interdependent, and programmers often learn concepts in a complex order, sometimes attempting to grasp advanced topics without mastering the basics. Following a well-designed curriculum that organizes DSA topics with minimal dependencies is advisable.
  • Avoiding complex explanations of concepts: Programmers often get stuck with complex jargon and poor explanations, leading to repeated attempts to understand the same idea or rejecting topics without fully grasping the concepts. This results in wasted time, reduced interest in the subject, and a habit of rote learning.
  • Understanding fundamental concepts and principles: To gain expertise in data structures and algorithms, it is crucial to comprehend the fundamental concepts and principles rather than merely memorizing them. This involves working on problems, critically thinking about solutions, and analyzing different approaches. Developing a logical approach helps apply these concepts to new problems and devise creative solutions.
  • Thinking about diverse solutions: Many programmers excel in coding but struggle with devising efficient solutions. They often attempt to solve many problems without thoroughly analyzing them, thus missing efficient solutions. Spending adequate time analyzing problems and exploring different patterns that lead to more efficient solutions is key.
  • Learning good coding practices: Sometimes programmers struggle to write correct code. If identifying a solution is an art, crafting correct code is a skill that requires focus, patience, and time. This includes practicing programming concepts, implementation patterns, types of programming errors, proper initialization, base cases, edge cases, and most importantly, developing a good coding style.
  • Overcoming fear of mathematics and logic: Data structures and algorithms require an understanding of mathematical topics such as permutations, combinations, summations, logarithms, number theory, recursion, etc. These topics are essential for solving problems and analyzing algorithm efficiency. Improving mathematical understanding and analytical skills involves:

— Practicing DSA-related math problems through online resources with exercises and explanations.

— Taking discrete mathematics courses to easily grasp DSA-related mathematical topics.

— Working on coding problems and analyzing their time and space complexity using the Big O notation, simplifying algorithm analysis.

— Collaborating with others to understand different approaches to algorithm analysis, especially if a peer or mentor has a strong background in mathematics.

  • Enhancing coding interview skills: Designing an efficient solution during an interview, while being scrutinized, is challenging for many programmers. As interviewees, it is crucial to communicate thoughts clearly and aloud to the interviewer. Writing code and communicating simultaneously is a necessary skill. Ignoring this skill can result in rejection despite strong coding and problem-solving abilities. Interviewers look for candidates who can manage multiple critical situations smoothly during work.
  • Overcoming doubts about solutions: Discussion is vital in learning DSA. Sometimes, critical doubts require immediate resolution for progress. At the beginning, programmers may be unsure of which questions to ask. Thus, forming a group or joining a community where mutual help can address doubts is essential.

By addressing these challenges and employing the suggested solutions, individuals can improve their understanding and implementation of algorithms and data structures, leading to more efficient and effective problem-solving skills.

6. Algorithmic Thinking

In this section, we will explore Algorithmic Thinking, a relatively new concept in the field, often regarded as one of the core ideas in Computational Thinking. While learning common algorithms individually is beneficial, it is more advantageous to develop a habit of algorithmic thinking. Training our minds to understand and follow algorithmic logic makes writing algorithms much more intuitive.

Do algorithms make you anxious? Do they seem complex and difficult to grasp? Are you unsure of what they actually are? If you feel any of these emotions or think you can’t become a good programmer or developer, you’re not alone. Algorithms and data structures often evoke fear and a sense of inadequacy in the world of software development. Traditionally educated developers might have taken a couple of classes on them, while self-taught developers often encounter them through Bootcamps. For most beginner developers, however, algorithms and data structures are a source of anxiety and imposter syndrome.

Algorithmic thinking involves a mental shift from how we typically think as humans. It is a more systematic way of thinking about problems and solutions, resembling how a computer executes tasks. This shift is surprisingly difficult because we unconsciously create shortcuts, assumptions, and rules that help us solve everyday problems without much thought. For example, if we want to sort ten numbers, we can quickly look at them, understand the order, and sort them correctly. However, we’re not used to breaking down our thought processes into discrete steps that can be translated into something a computer can do. Computers can’t randomly jump to different places in a dictionary to find a word based on its spelling; they need very specific instructions on where to start and how to proceed.

The importance of algorithmic thinking lies in two key coding problem-solving skills in programming:

  1. Step-by-Step Design of an Efficient Solution: This requires systematic thinking about the problem.
  2. Translating the Solution into Correct Code: This involves implementing the designed solution effectively.

Some programmers may struggle with the first skill, which requires algorithmic thinking. During interviews, some employers may be more interested in how a candidate approaches a problem rather than the actual implementation of the solution. Demonstrating expertise in algorithmic thinking can impress a potential employer.

Like any skill, algorithmic thinking can be learned and requires practice. It is similar to assigning code to classes in object-oriented design (OOD); you do your best, identify weaknesses, and refine your solution. Here are several guidelines to help you develop algorithmic thinking more quickly.

Essentially, algorithmic thinking involves solving a problem in a systematic way, relying on principles of logic and iteration. The steps include:

  1. Precisely Define the Problem: Clearly understand what is being asked.
  2. Break Down the Problem into Smaller, Simpler Parts: Simplify complex problems into manageable chunks.
  3. Define Solutions for Each Part: Create strategies for each simplified part.
  4. Implement the Solutions: Write code for the solutions.
  5. Review and Improve: Continuously refine and optimize the solutions.

Before we delve into learning algorithmic thinking strategies, let’s revisit the definition of an algorithm. An algorithm is simply a method for performing tasks. It’s a process for solving a type of problem such as:

  • Finding a word in a dictionary.
  • Sorting a list of numbers.
  • Generating the Fibonacci sequence.
  • Finding prime numbers.
  • Baking a cake.
  • Doing laundry.
  • Making a sandwich.

While some algorithms are indeed complex, requiring deep knowledge of computer science theories, machine learning, and mathematics, this does not mean that all algorithms are inherently difficult. To start thinking algorithmically, one can approach challenges in two ways: by breaking down the problem and constructing the solution. It’s beneficial to begin by dissecting the problem and only then build the solution.

Spending time deconstructing a problem helps us better understand it and see how solutions naturally emerge from this initial understanding. This method is especially useful to avoid feeling overwhelmed when faced with a new problem outside of your comfort zone.

Let’s consider the problem of finding a word in a dictionary. Suppose the dictionary contains a list of words. For search problems, we typically need to know:

  1. Where and how to start the search;
  2. When and how to stop the search;
  3. How to compare two items in the list to determine which one comes before the other;
  4. How to proceed with the search if the word has not yet been found.

The better the algorithm, the shorter the time between steps one and two, and the fewer times we need to perform steps three and four.

For the dictionary search problem, we can improve upon the above steps and break down the problem as follows:

  1. The expected order of words (e.g., alphabetical order);
  2. How to compare two different words and determine which one should come before the other;
  3. How to know when we have found the word;
  4. How to know if the word is not in the dictionary.

Assuming steps one and two are solved by the Persian alphabetical order and that we can easily determine the order of words based on their alphabetical characters, we move on to step three. We know we have found the word when it exactly matches the word we are searching for at our search position. For step four, assuming the previous steps have been correctly executed, if we reach the end of our search without finding the word, we conclude that the word is not in the list.

To start thinking about problems algorithmically, it is helpful to begin by considering a small and simple data set. The size should be manageable enough to think through easily and, if necessary, write or draw it out physically.

In mathematics, there is a process called proof by induction. If we can prove that a mathematical formula works for a single case and assume it holds for n-1 cases (where n is an arbitrary number), we then attempt to prove it for the n-th case. If the formula holds for the n-th case, it should hold for any number of cases.

For the dictionary search example, if we can do it correctly for one item and then for ten items, we can likely do it correctly for any number of items. This process helps us understand the details and identify subtle pitfalls of the problem.

6.1. How to Create an Algorithm with Algorithmic Thinking?

It can be very tempting to start solving the problem by jumping directly to creating a solution. However, starting with building a solution for a generic problem is often the beginning of coding. It is natural to want to dive right in, but it might lead to frustration if we realize we can’t solve it as initially thought. This process is akin to realizing halfway through baking a cake that we don’t have all the ingredients or need to know a specific mixing technique for proper baking.

Without fully understanding the problem, we might not create the best solution, or it might take longer to reach it.

After breaking down and understanding the problem, we are ready to build the solution. At this stage, breaking the solution into smaller components is important. Each part of the solution should address one or more identified aspects of the problem.

The approach to building the solution can vary; some start with the simplest and most straightforward part, while others tackle the most challenging parts first.

For the dictionary search, the solution might be constructed as follows:

  1. Write the loop (or recursive function);
  2. Write code to exit the loop/recursion if the word is found;
  3. Write code to exit the loop if the word is not found and the dictionary is exhausted;
  4. Write code to decide how to continue the search if the word is not found but the dictionary is not empty;
  5. Handle special cases, fix bugs, and address other details (e.g., what happens if an empty list is passed).

6.2. Mastering Algorithmic Thinking

Search and sorting algorithms are good starting points for mastering algorithmic thinking because they prompt us to consider:

  • How new algorithms are created;
  • How algorithms are improved;
  • How to determine the efficiency of an algorithm;
  • How to choose between different algorithms.

Search and sorting are related and usually build on each other. Starting with these algorithms allows us to see how we can begin with a simple algorithm and gradually improve it as we learn where and how it is inefficient.

As we gradually build the solution from small, simple parts to larger, more complex ones, each step should remain manageable and independent. This way, when something doesn’t work correctly, the potential causes are smaller and easier to identify. We should allow ourselves to explore different solutions and accept that it might take several attempts and more time to create an efficient and optimal solution.

Even though we may never need to implement each of these algorithms as professional developers, efficient search and sorting algorithms are now included in the standard libraries of most programming languages. But understanding and being able to write these algorithms remains important. They form the foundation for understanding algorithms as a whole, teaching us the real impact of algorithm efficiency and how newer, more efficient, and complex algorithms are developed.

6.3. Practicing Algorithmic Thinking

Now that we are familiar with algorithmic thinking, it is time to practically understand the problem-solving steps in programming based on this kind of thinking and to develop algorithmic thinking through practice with these steps. Initially, it is important to know that to solve any problem, one must follow a series of defined steps. Practicing these steps can help us save time, identify commonly used patterns in various coding problems, and effectively find solutions for even the most complex issues

Step 1: Understanding the Problem Statement

To effectively solve a problem, it’s crucial to clearly understand what is being asked. This includes understanding the overall problem and asking various questions such as:

  1. Do we understand every word used in the problem statement?
  2. What data or information is provided as input?
  3. What data or results are requested as output?

Moreover, it’s important to grasp both computational and non-computational details of the problem such as the data structures used, input distribution, specific constraints on the input, and relevant mathematical properties.

Begin by answering the following questions:

  • What are the inputs and outputs?
  • What type of data is available?
  • How large or what scale are the inputs?
  • How are the data stored? What is the data structure?
  • Are there any specific conditions or orders in the data?
  • What rules exist for working with the data?

Step 2: Choosing Concepts and Solution Strategies (Thinking of a Preliminary Correct Solution)

After analyzing the problem description, we should make predictions about the concepts and approaches needed to solve it. We can consider the following questions:

  • Do we need to use all the information provided in the problem?
  • Can we eliminate any unnecessary information?
  • Which conceptual ideas relate to the given problem?
  • Which approach would be more appropriate for processing the input data and achieving an efficient solution?
  • Have we solved similar problems in the past? If yes, how can we use that experience to our advantage?

Identifying concepts and approaches used to solve similar problems can save significant time and energy.

Step 3: Designing an Efficient Solution with Pseudocode

To design a good solution, it’s best to first explore several examples with a handwritten approach and develop a general step-by-step strategy. Moving from a basic algorithm to the most efficient algorithm in one step can be challenging. Each time, we should optimize the previous algorithm until no further optimization is possible. Two types of thinking are important at this stage:

  • Iterative thinking: Gradually solving the problem by creating a partial solution;
  • Recursive thinking: Solving the problem using smaller subproblems.

It is advisable to describe on paper the operations needed to convert the given input into the desired output. Steps can be written in plain language and then converted into pseudocode or a flowchart. This facilitates the writing of the correct final code.

Step 4: Implementation and Converting Pseudocode into Correct and Optimized Code

Once a solution is created using pseudocode, it can be implemented in a programming language like C++, Java, or Python. During this process, the precise selection of programming elements that help create optimized code is crucial. This may include elements such as helper functions, loops, and variables like local variables, global variables, and pointers.

Also, attention to memory management, preprocessing, and other details that can affect the efficiency and correctness of the code is important.

Step 5: Verifying Correctness and Further Optimization

After implementing the solution, it is important to test it for problems, analyze its time complexity and space complexity, and consider ways for further optimization. Here are some ideas that might be useful:

  • Manually trace the input-output pattern or diagram the behavior of variables or critical stages defined in the solution.
  • Identify input cases that cause the algorithm to produce incorrect output. If there is an error or issue, identify and correct the relevant steps. Ensure the solution manages all edge cases.
  • Analyze the efficiency of the solution by counting the number of operations relative to the size of the input.
  • Try to optimize the solution by identifying key details of the problem and striving for a different problem-solving approach. Continue optimizing the solution until no further improvements are possible. Sometimes, reducing intermediate steps in pseudocode can optimize the solution code.

Like any skill, practicing algorithmic thinking leads to improvement. However, improvement in algorithmic thinking differs from improving physical skills, as physical skills can be repeatedly done in the same way and gradually improved. In the case of algorithms, simple repetition won’t help much. Although useful, striving to find new algorithms and re-implementing and evaluating them leads to improvements in algorithmic skills. This can be enhanced by practicing coding on online platforms like LeetCode, HackerRank, or participating in online courses available on sites like Udemy, Coursera, and Codecademy.

7. Conclusion

This article comprehensively explores the importance and applications of algorithms and data structures in programming and software development. As fundamental pillars of computer science, algorithms and data structures play a crucial role in enhancing efficiency, optimizing resource use, and ensuring the scalability of programs. These concepts are highly effective in developing problem-solving skills and logical thinking in programmers and are essential for mastering advanced computer science topics such as machine learning and data science.

Learning data structures and algorithms aids in improving problem-solving skills, including defining, analyzing, selecting, implementing, evaluating, and reviewing solutions. Understanding how to use appropriate data structures and algorithms allows for the rapid development of efficient and high-performance code. Furthermore, a deep understanding of advanced computer science concepts built on data structure and algorithm principles facilitates learning newer and more complex concepts. Employers highly value DSA skills as they demonstrate the ability to create intelligent solutions.

The article also addresses the challenges of learning and implementing algorithms and data structures. Issues such as poor design, inappropriate data structure selection, and implementation problems can hinder learning. Misconceptions about the complexity of algorithms and the importance of continuous learning highlight the need to understand fundamental concepts and develop algorithmic thinking to overcome these challenges.

Familiarity with algorithmic thinking as a mental shift encourages programmers to approach problems systematically and logically instead of relying on shortcuts and unwritten rules. This type of thinking is essential for solving coding problems and designing efficient solutions. Algorithmic thinking involves the steps of precisely defining problems, breaking them down into smaller and simpler parts, defining solutions for each part, implementing the solutions, and reviewing and improving them.

By fostering a deep understanding of algorithms and data structures and adopting algorithmic thinking, programmers can develop more effective problem-solving skills, leading to the creation of efficient and scalable software solutions.

It is hoped that this discussion was insightful and valuable. Sharing experiences, insights, or any ideas is highly encouraged. Let’s continue learning and growing together!

--

--

MahdiehMortazavi

Machine Learning & Deep Learning Enthusiast | Data Analyst | Evolving Data Scientist