Yalco's Easiest Data Structures and Algorithms

This course makes the core concepts of data structures and algorithms easy to understand through visual metaphors and testing tools. You will gain practical experience by implementing everything from the basics to sorting and searching.

(4.9) 111 reviews

1,226 learners

Level Basic

Course period Unlimited

Algorithm
Algorithm
data-structure
data-structure
Algorithm
Algorithm
data-structure
data-structure

Reviews from Early Learners

Reviews from Early Learners

4.9

5.0

HJuhoney

97% enrolled

The price efficiency and time efficiency are both incredible. Things that were confusing even after staring at expensive lectures for a long time, I understood everything by binge-watching for just 3-4 hours. I haven't tried the testing tools and practice code yet, but just watching the videos alone makes this lecture more than worth the money. Highly recommended.

5.0

doob9p

32% enrolled

The animations you created for the lectures make them so easy to understand, and I never lose focus while watching! Especially the way you made it possible to test each data structure with a UI interface is absolutely amazing🔥

5.0

Jy._s

56% enrolled

I always got stuck on the recursive parts when it came to trees and gave up, but through this lecture I was finally able to understand it all the way through. The flow of returning to the previous function through return and connecting nodes was especially confusing, but thanks to the instructor's explanation, that part was resolved so satisfyingly! Now I can visualize how trees are constructed in my head^^ Thank you!

What you will gain after the course

  • Key concepts of algorithm performance, such as time complexity and space complexity

  • Principles and implementation of major data structures such as arrays, stacks, queues, trees, and graphs

  • Comparison of how various sorting algorithms, such as bubble, merge, and quick sort, work and their efficiency.

  • Understanding algorithms that frequently appear in coding tests and practical work, such as DFS and BFS traversal.

  • Improving data structure and algorithm implementation skills through hands-on practice using Java and Python.

https://youtu.be/d2X38zE7VsU

After leaving a like and a comment on the YouTube video above (the public part of this course),
send a screenshot to yalco@yalco.kr
and we will send you a discount coupon to take the course at half price.chúng tôi sẽ gửi cho bạn mã giảm giá để có thể tham gia khóa học với giá bằng một nửa.

Data structures and algorithms are the fundamentals for every developer and the core of coding tests and practical work.
However, the concepts are difficult, and it's hard to get a feel for them just by reading books.
This course clears away that frustration through realistic analogies, visual aids, and hands-on practice where you actually 'touch' the material.
Without complex jargon, we teach only the essential core concepts easily and clearly.
If you want to build a solid foundation from the basics, start with this course right now.

👌 OK even if you only know one of the two: Python or Java!

👆 On the left is the Python code

👆 The right side is Java code

All examples in the lecture (excluding dynamic arrays due to language characteristics) are explained using both Python and Java code simultaneously.

Even if you only know one of the two languages, you can still take the course, and if you have learned languages with similar syntax to Java, such as JavaScript or C#, you can follow along without much difficulty.

Observing the differences between the two languages while looking at the code explained simultaneously will also be a great learning point.

🕹 Data Structures and Algorithms: Learning by Touching and Manipulating Directly

We provide the testing tools shown above for all data structures and algorithms covered in the lecture.

We have designed it so that you can input values yourself, execute functions, and observe each process step-by-step.

For each operation, the time complexity and space complexity are displayed, allowing you to gain a deep understanding of each data structure and algorithm.

👇 Click to preview!

💡 High-quality video lectures by Yalco, the master of explanations

Yalco, the YouTuber who explains even the most difficult and complex concepts in a snap, will help you understand intricate data structures and algorithms all at once through metaphors and graphics.

Subtitles are provided for every scene, and code is explained with intuitive indicator lines instead of typing, allowing you to experience fast, easy, and convenient learning.

🖱 All examples provided as copy-pasteable snippets

Notion pages are provided for each lesson where you can check/copy the example codes and access test pages. You can use these to learn more conveniently and efficiently.

Recommended for these people!

Job seekers preparing for coding tests

Computer Science majors encountering CS subjects for the first time

Developers who want to build a solid foundation of concepts

  • Those who are not familiar with time complexity and data structures,
    or those who haven't had the time to organize them.

  • Those who want to start preparing for coding tests
    while solidifying concepts through hands-on practice

  • 1st and 2nd-year students who found data structures/algorithms classes difficult

  • Those who felt that explanations from books or professors were too abstract

  • Those who want to grasp core concepts through visual explanations and hands-on practice

  • Those who are familiar with practical work but feel their understanding of basic concepts is shaky.

  • Those who want to rebuild their foundation from scratch and strengthen both theory and implementation.

📋 Here is what you will learn.

1. Complexity

  • The meaning of time complexity and space complexity

  • How to write and interpret Big-O notation

  • Major complexity types and practical examples


2. Arrays and Lists

  • Definition and memory structure of arrays

  • Index access, element modification, and full traversal

  • Principles and costs of insertion and deletion operations

  • Array-based linear search

  • Conceptual differences between lists and arrays


3. Stacks and Queues

  • Structure and operations of a stack: push, pop, peek

  • Structure and operations of a queue: enqueue, dequeue

  • Call stack concepts and principles

  • Array-based and linked list-based implementations


4. Trees

  • Structure of a binary tree: root, node, leaf, height

  • Tree traversal methods: Preorder, Inorder, Postorder, Level-order

  • Concepts of Binary Search Tree (BST) and rules for insertion/search

  • Rotation and balance conditions of AVL trees

  • Red-Black Tree color rules and characteristics

5. Sorting

  • Bubble Sort, Selection Sort, Insertion Sort

  • Merge Sort, Quick Sort, Heap Sort

  • Comparison of how each algorithm works

  • Time complexity and best/worst cases for each sorting algorithm

  • Efficiency and use cases in practice


6. Hash

  • Hash functions and hash index calculation

  • Collision resolution methods: Chaining, Open Addressing

  • Storing and searching key-value pairs

  • Time complexity analysis of Hash Maps

  • Simple Hash Table Implementation


7. Graphs

  • Components of a Graph: Node (vertex), Edge (edge)

  • Directed Graph vs. Undirected Graph

  • Differences based on the presence or absence of weights

  • Implementation of Adjacency List / Adjacency Matrix methods

  • DFS (Depth-First Search) and BFS (Breadth-First Search) algorithms

  • Shortest Path Algorithms (Dijkstra, Floyd-Warshall, Bellman-Ford)

  • Minimum Spanning Tree Algorithms (Kruskal, Prim)

Notes before taking the course

Learning Materials

  • The test tools and example codes used in the lecture are provided via a Notion page.

Prerequisite Knowledge and Important Notes

  • Basic knowledge to the extent of being able to read Python and Java code

    • Or knowledge of languages similar to Java, such as JavaScript or C#.

Recommended for
these people

Who is this course right for?

  • Those taking Data Structures & Algorithms classes

  • Those who are preparing for coding tests

  • Those who wish to grow further as developers

Need to know before starting?

  • Basic knowledge of Python or Java (or similar languages)

Hello
This is yalco

34,165

Learners

1,960

Reviews

96

Answers

4.9

Rating

17

Courses

I am the YouTuber behind the channel Yal-co's Coding Dictionary, as well as an author of IT books. Drawing on my experience as a full-stack developer, I create content that explains difficult programming concepts through metaphors, simple examples, and sometimes animations to make them easy for beginners to understand.

🎬 YouTube Yal-co's Coding Dictionary Channel (Click!)
📕 View Yal-co's Books (Click!)

More

Curriculum

All

34 lectures ∙ (4hr 36min)

Published: 
Last updated: 

Reviews

All

111 reviews

4.9

111 reviews

  • jyseo님의 프로필 이미지
    jyseo

    Reviews 54

    Average Rating 5.0

    5

    56% enrolled

    I always got stuck on the recursive parts when it came to trees and gave up, but through this lecture I was finally able to understand it all the way through. The flow of returning to the previous function through return and connecting nodes was especially confusing, but thanks to the instructor's explanation, that part was resolved so satisfyingly! Now I can visualize how trees are constructed in my head^^ Thank you!

    • aquswitpo5474님의 프로필 이미지
      aquswitpo5474

      Reviews 10

      Average Rating 5.0

      5

      97% enrolled

      The price efficiency and time efficiency are both incredible. Things that were confusing even after staring at expensive lectures for a long time, I understood everything by binge-watching for just 3-4 hours. I haven't tried the testing tools and practice code yet, but just watching the videos alone makes this lecture more than worth the money. Highly recommended.

      • brook님의 프로필 이미지
        brook

        Reviews 1

        Average Rating 5.0

        5

        32% enrolled

        The animations you created for the lectures make them so easy to understand, and I never lose focus while watching! Especially the way you made it possible to test each data structure with a UI interface is absolutely amazing🔥

        • gzenden님의 프로필 이미지
          gzenden

          Reviews 10

          Average Rating 4.9

          5

          9% enrolled

          This time, while participating in Hyangro's Chuseok challenge, I realized I had no basic CS knowledge at all, so I signed up for classes to fill in those gaps. As expected, Yalco's animation-style lectures go straight to my ears so smoothly that it makes me feel great 😊😊

          • minganta888675님의 프로필 이미지
            minganta888675

            Reviews 11

            Average Rating 4.9

            Edited

            5

            62% enrolled

            It feels so hollow that I struggled all this time when you just told me so easily Just listen to this

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