The best way to start learning data structures easily: with minimal theory and maximum understanding.

Without complex mathematical formulas or abstract theories, the essence of data structures is explained in an easy and fun way with fun real-life examples, illustrations, and code that only contains the core.
It systematically guides developers through the data structures they must know, including arrays, Big-O notation, linked lists, stacks, queues, heaps, binary search trees, and graphs.
You can also naturally develop a sense of when to choose which structure.
If you want to build your foundation as a developer, prepare for coding tests, or better utilize data structures in your work, this book will be a great starting point.
Let's start the world's friendliest data structures class right now.

If you're reading this book, you probably know that we live in what's commonly referred to as the "data age."
In this era, data has become an indispensable element of our lives, and thanks to technological advancements, the speed of information production is increasing exponentially more than ever before.
This massive flow of data is changing how we live, work, and even communicate with each other.
/ To properly understand this vast amount of information and avoid being overwhelmed by it, we need a way to organize the information effectively.
This is where data structures come into play.
Data structures are the way computers and programs store and organize information, helping them manage and manipulate data more efficiently.

--- p.3

After much crying and arguing, Kim's parents finally agreed to provide a new display case to house her new trophies.
But he set a condition.
The existing display case cannot be expanded and must be discarded, and the cost of purchasing a new display case and disposing of the old one must be paid for with money from Kim's piggy bank.
If she doesn't have enough money to buy a new display case, she'll have no choice but to throw away some of her old robots.
/ So Kim has no choice but to find the optimal strategy to save as much money as possible in the long run (she might consider using modular furniture).
That's true, but let's assume for this analogy that we don't provide a modular solution.

--- p.64

The team is developing their first video game.
A quick look at the game reveals that it is a side-scroller where the protagonist moves from left to right within a building, moving from one room to another.
The team carefully designed the rooms and implemented each one individually.
Now all that remains is to model the progression between rooms.
/ 'What should we do with this?' the team pondered.
/ The framework the team uses basically provides a singly linked list, which can save a lot of development time.
However, if a singly linked list is used, the game protagonist can only go to the right room and cannot go back.
--- p.92

Priyanka recently joined a startup that, from the outside, looks absolutely fantastic.
Their mission resonated well with her, and the AI ​​technology the founders developed was also appealing.
But she had no idea that, beyond its core technology, the company's infrastructure and organization were in shambles.
She didn't even have a proper task management tool, and her bug backlog consisted of sticky notes taped to her desk, monitor, and small kitchen table.
/ So, 'scrolling' through the backlog meant collecting these sticky notes, searching around the office, deciphering the handwriting, or trying to figure out who wrote them.
In these situations, it's easier to miss and forget about bugs than to fix them.
After missing a week of bug fixes and receiving a red flag, Priyanka couldn't take it anymore.

--- p.137

Mario has a good memory, but now that he has collected hundreds of cards, he has trouble remembering which ones he already owns and which ones he doesn't.
This is especially true when trading cards with friends, as you need to quickly choose a card before the other person takes it.
To stay ahead of the competition, Mario plans to utilize a mobile app that lets players scan a card with their camera and see in seconds whether that card is already in their collection and how many copies they have.
/ The core feature of this app (besides p.UX and object recognition) is the dictionary.
A dictionary stores data with a specific key and retrieves data based on the key.
For baseball cards, you can use the player's name or even a photo of the card as a key.
In this example, the key could be associated with an attribute such as the number of copies of a card you own, or details about the card (team information, statistics, etc.).

--- p.197

According to information gathered by the campaign manager, the rabbit is a social network star, and gaining its support could change the course of the election.
Tiger Headquarters wants to understand how far Rabbit has fallen from his friend chain.
He also wants to know what the shortest path is between the tiger and the rabbit.
The plan is to start with one of Tiger's friends, who will introduce Tiger to another of their friends, who will then introduce Tiger to another of their friends, and so on.
This process is repeated until the rabbit is reached, with the shorter the path, the fewer people involved.
/ The breadth-first search (BFS) algorithm does exactly this.

--- p.226