Awakening Elementary School System in University

Chen Lin listened to Sun Yu’s explanation while quickly scanning the problem on the paper.

His expression was as calm as still water, but in his mind, "Little Mathematician" had already kicked into gear, and his brain’s processing speed was skyrocketing.

To an ordinary person, the mathematical symbols and engineering terms on the page might seem profound and obscure, but in his eyes, they were like clear, distinct LEGO bricks.

[Mapping model... Actual position P_actual = (x_actual, y_actual)... Commanded position P_cmd = (x_cmd, y_cmd)... Error components δx, δy, εxy...]

The moment these conditions entered his sight, his brain didn’t even need to consciously "think." A complete and logically rigorous mathematical expression surfaced as naturally as water flowing into a channel.

[Optimization problem... Discrete measurement data... Identifying the error component functions... Minimizing the sum of squared prediction errors...]

When he saw the second part of the problem, a series of related mathematical tools like the least squares method, polynomial fitting, and gradient descent were instantly and automatically filtered and combined in his mind, forming the solution process.

"...So, the core of this problem is to first establish a mapping relationship from the theoretical coordinates to the actual coordinates based on the principles of error. Then, we need to design an optimization algorithm to reverse-engineer the exact error at any given point on the entire worktable using the known measurement data."

Sun Yu finally finished his detailed explanation of his understanding of the problem.

He looked up at Chen Lin, full of anticipation, wanting to see if his boss was satisfied with his work.

And then, he saw the undisguised smile of approval on Chen Lin’s face.

"Sun, nice work," Chen Lin praised him sincerely. "You really nailed it. You stripped away all the messy engineering background, leaving just a pure math problem."

The praise made Sun Yu’s heart bloom with joy. He scratched his head good-naturedly and chuckled.

Chen Lin nodded in satisfaction. Just as he was about to find some scratch paper and a pen to solve the problem in a flash, the corner of his eye inadvertently caught sight of Shen Yan standing quietly to the side.

He saw that she had moved closer at some point. Her fine brows were slightly furrowed, and her crystal-clear eyes were fixed on the A4 paper in his hand, clearly deep in thought as well.

An idea sparked in Chen Lin’s mind, and a playful mood struck him.

He held the problem sheet out to Shen Yan with a slight smile and asked, "How about it, our top student? Care to take a crack at it first?"

Hearing this, Shen Yan was momentarily stunned, and a barely perceptible blush crept onto her fair cheeks.

She hesitated for a moment before finally shaking her head gently, a trace of candid helplessness flashing in her clear eyes.

"Um... I can roughly figure out which concepts are needed, like using a rotation matrix to handle the perpendicularity error, and for the optimization problem later on, it probably requires the least squares method for fitting..."

Her voice was soft, but her train of thought was exceptionally clear. As expected of a top student from the School of Mathematics, she had accurately grasped several core approaches to the solution with just a single glance at the problem.

"But..." Her tone shifted, now tinged with a hint of regret. "When it comes to choosing the most suitable function model to identify the error components, and how to design an optimization algorithm with the fastest convergence speed... there’s a lot I haven’t learned yet. And even for what I have learned, my understanding isn’t deep enough."

She looked up at Chen Lin, her eyes holding not a trace of jealousy or unwillingness, only a pure yearning for a higher level of knowledge and an expectation that had long since become familiar.

Sun Yu, for his part, showed no extraneous emotion at all. He simply turned around silently, pulled a stack of pristine A4 paper from a nearby unopened box of printer paper, found a brand-new gel pen in his pencil case, and placed them on the desk in front of Chen Lin.

As for Chen Lin’s ability to instantly solve any math problem, the two of them had long ago moved past the initial shock and numbness to a state of taking it for granted. They had even come to secretly look forward to it as a "performance."

Seeing their reactions, Chen Lin found it quite amusing.

He didn’t say any more, slapping the problem sheet onto the desk, picking up the pen, and leaning back comfortably into the brand-new ergonomic chair.

"Alright then."

He flexed his wrist, letting out a few crisp CRACKS.

"Then you two had better watch closely."

As soon as the words fell, he leaned forward, and the tip of his pen gently touched the snow-white scratch paper.

The office fell silent in an instant.

Sun Yu and Shen Yan both subconsciously held their breath, their gazes glued to the trajectory of Chen Lin’s pen tip.

At first, the two of them could barely keep up with Chen Lin’s train of thought.

He began by fluidly writing out a series of basic coordinate transformation formulas, linking the machine tool’s theoretical commanded position with the actual measured position. This was a step that any math student with a solid foundation could understand.

But immediately after, the whole atmosphere changed.

Not only did Chen Lin’s writing speed not slow down as the problem grew more complex, it actually got faster and faster!

Complex mathematical symbols and dazzling strings of matrix operations flowed from his pen.

The error component functions that, in Sun Yu’s view, would require consulting a vast amount of reference material and repeated deliberation to determine were written out directly and without hesitation by Chen Lin.

A mere five minutes later, Sun Yu had given up on thinking entirely. He was completely dumbfounded.

He now felt like he wasn’t watching someone solve a problem, but rather a thrilling calligraphy performance.

Even though he couldn’t understand a single thing being written, he just felt... it was badass!

Shen Yan, on the other hand, held on for a bit longer than Sun Yu.

Relying on her extraordinary mathematical talent and solid theoretical foundation, she could still barely recognize some familiar theoretical frameworks within the formulas Chen Lin was writing.

But as time went on, the expression on her face gradually shifted from initial concentration and contemplation to deep shock and bewilderment.

Chen Lin’s method of solving the problem had completely surpassed the scope of her understanding.

He didn’t stick to any single specific model suggested by the problem. Instead, he wrote out three completely different approaches to constructing the error function model side-by-side.

But the third approach was what made Shen Yan’s scalp tingle.

Chen Lin had actually built a small-scale neural network model from scratch, right on the spot!

He not only clearly wrote out the network architecture and activation functions, but he even provided a concise analysis of the pros and cons of different optimizers. In the end, he went so far as to directly provide the closed-form solution for the optimal fitting coefficients!

It was an almost unreasonably overwhelming solution, like an attack from a higher dimension!

When Chen Lin’s pen drew the final symbol signifying the end in the bottom right corner of the scratch paper, the clock on the wall showed that exactly fifteen minutes had passed.

"Done."

Chen Lin tossed the pen onto the desk, gave a big stretch, and leaned all the way back into the comfortable ergonomic chair.

He replayed the problem-solving process in his mind and made a silent comment.

’This problem is only about average in difficulty.’

The final exams for the five specialized courses Professor Gu Ming had given before... the hardest problem on each of those papers was probably more difficult than this one.

He remembered clearly that each of those exams had one problem that was significantly harder than the rest, taking him at least twenty minutes or more to solve.

’Looks like this company, Era of Creation, is pretty legitimate after all.’

Chen Lin recalled surfing the web and seeing many netizens complain that some small-time, crafty companies liked to package their own technical problems as interview questions, milking interviewees for free solutions.

The problem Era of Creation had given was moderately difficult. It could effectively test the solver’s abilities without involving their real core secrets. It was, indeed, a proper test question.