After Paris Saint-Germain was removed from the list, I led England to victory!

The draw for the next round of the EFL Cup brought a sigh of relief to Arsenal, as their opponent was Southend United from League One.

For Arsenal, who are aiming for the league and the Champions League, this is undoubtedly an excellent opportunity to train and rotate their squad.

Professor Wenger stood at the edge of the training field, watching his students sparring in groups.

His gaze fell on Yan Yuan.

His protégé has just experienced intense matches against Juventus in the Champions League and a resounding victory over Spain in the UEFA Nations League. In the previous few Premier League matches, he also played the full 90 minutes in every game, contributing decisive goals and assists.

Yan Yuan's form remains red-hot, but Wenger knows that even the most powerful engine needs maintenance.

"Yan," Wenger called Yan Yuan aside after training, his tone gentle but with an undeniable decision, "You'll be rested for the League Cup match against Southend this weekend."

Yan Yuan was taken aback for a moment, then understood the coach's intention.

He has indeed been working non-stop lately. Although he is physically fine, he is experiencing mental fatigue.

More importantly, right after the EFL Cup ends, there will be a major event: the North London Derby!

Away game against city rivals Tottenham Hotspur!

That's the real battlefield where he needs to be fully prepared.

"Okay, Coach." Yan Yuan nodded readily without objection. "I understand. I also need to take care of some academic matters."

Wenger patted him approvingly on the shoulder: "Very good. Take advantage of these few days to rest and get in shape. We need you at 100% for the next derby."

The news of his rotation leave brought Yan Yuan a sense of relief, but also a sense of urgency.

It's relaxing because the body can catch its breath.

The urgency stems from the fact that a phase exam on Imperial College London's online platform is approaching.

This course involves algorithm analysis and complex system modeling, and it is quite difficult, with a high proportion of the exam content.

He'll need to practice some coding problems these next couple of days.

……

Yan Yuan did not travel with the Arsenal team on Saturday afternoon as their bus headed to Southend United's home ground.

He changed into a simple casual outfit: a dark jacket, jeans, and sneakers, and carried a backpack containing a laptop and thick textbooks.

I stepped into the magnificent and solemn main library of Imperial College London for the first time.

In stark contrast to the hustle and bustle of the Emirates Stadium, the library was filled with an almost sacred tranquility.

Sunlight streamed in through the huge arched glass windows, casting dappled shadows on the dark wooden desk.

The only sounds in the air were the rustling of pages turning, the soft scratching of pens on paper, and the occasional, deliberately hushed murmur of discussion.

Yan Yuan found a quiet corner spot by the window, away from the crowds.

He put down his backpack, took out his laptop and the thick book "Introduction to Advanced Algorithms and Quantitative Financial Models".

He took a deep breath, trying to temporarily suppress his passion on the field and immerse his mind in the world of logic and code.

He opened the online exam simulation system and started doing the questions.

He solved the basic questions relatively smoothly, thanks to his solid self-study foundation and good logical thinking.

But soon, a question about "the implementation of optimization algorithms for Monte Carlo simulation in the pricing of complex financial derivatives" stopped him in his tracks.

The task requires him to analyze the efficiency bottleneck of a specific Monte Carlo path generation algorithm in a parallel computing environment, and to design an improvement scheme to reduce computation time while ensuring accuracy.

This problem provides a partial core code framework, but Yan Yuan needs to fill in the key optimization logic.

Yan Yuan stared at the code framework and complex mathematical formulas on the screen, his brows furrowed.

He tried to recall the theories from the textbook, flipped through the notes he had brought, and scribbled on the draft paper.

He tried several approaches: optimizing the choice of random number generator? Improving the vectorization of path generation? Adjusting the parallel task partitioning strategy?

However, the simulation results either decreased accuracy, or the efficiency improvement was not significant, or even worse.

Time passed second by second.

Yan Yuan had already spent nearly half an hour on this question.

He would sometimes type rapidly on the keyboard, debugging code; sometimes he would stop, bite his pen, and stare blankly at the screen; and sometimes he would scratch his hair in frustration and press his throbbing temples.

It's really a headache.

On the court, he can use speed and skill to break through defenses, but when faced with these cold codes and mathematical models, he felt somewhat powerless for the first time.

He slumped onto the table, let out a long sigh, and looked lost and exhausted.

Just then, Lin Jianwei, carrying a thick stack of reports with complex financial model charts printed on the cover, was quietly searching for an empty space along the aisle between the bookshelves.

Her gaze swept across the quiet corner and landed on a familiar figure slumped over the table, his back filled with dejection.

Lin Jianwei stopped in her tracks.

She recognized Yan Yuan.

That young man who amazed everyone at Professor Barbara's lecture and dominated the football field.

At this moment, he shed his sharp edge on the court and resembled an ordinary student struggling with a difficult problem, with a rare and even somewhat endearing sense of "confusion".

Lin Jianwei suddenly remembered.

She recalled her previous coldness and aloofness towards him, his later seriousness and hard work in academic settings, and the dramatic experiences she had uncovered about his life...

A complex emotion welled up inside me.

She is no longer the Lin Jianwei who viewed "star student" with prejudice.

Ever since the lecture ended that day, she has been convinced that the boy was genuinely trying to balance football and his studies, and had put in unimaginable effort.

This dedication and seriousness earned her the respect of her fellow student.

Lin Jianwei, carrying the documents, quietly walked up behind Yan Yuan.

His gaze slowly swept across Yan Yuan's desk, landing on the textbook Yan Yuan had opened: "Introduction to Advanced Algorithms and Quantitative Financial Models".

This book is from an area she studied in depth during her master's program and still frequently works on in her current research projects.

Looking at his computer screen again, there was that familiar code framework and problem description...

Lin Jianwei instantly understood where Yan Yuan was stuck.

She hesitated for a moment, but seeing how tormented Yan Yuan looked, she gently reached out her finger and carefully poked Yan Yuan's shoulder.

戳~

"Huh?" Yan Yuan was engrossed in his brain-teasing thoughts when he was startled by the sudden touch and abruptly looked up.

The two people looked into each other's eyes.

Yan Yuan's face flushed red instantly.

Today, Lin Jianwei wore a beige turtleneck cashmere sweater with a neatly tailored dark gray long trench coat. Her long hair was softly draped over her shoulders, and she wore light makeup. She exuded an intellectual, elegant, and slightly aloof beauty.

In the soft light of the library, her features appeared exceptionally delicate and charming.

"Um... Senior... Senior sister?" Yan Yuan stammered a little, and was also a little nervous.

Lin Jianwei looked at Yan Yuan's face, which flushed red instantly, and his eyes, which looked somewhat flustered. The corners of his mouth curved slightly, but he quickly regained his composure.

She lowered her voice and pointed to his computer screen:

"Are we stuck on the parallel optimization of Monte Carlo path generation? Especially the communication overhead issue for low-dispersion sequences in a distributed memory model?"

Yan Yuan's eyes widened instantly!

How did she know?

And you described it so accurately?

He nodded quickly, as if grasping at a straw, and whispered.

"Yes, yes, senior, this is it. I've tried several methods, but either the accuracy isn't enough, or the speed improvement is minimal, or it's even slower..."

Lin Jianwei nodded, gesturing for him to move aside a little.

Yan Yuan quickly moved aside.

Lin Jianwei put down the documents in her hand, leaned down, and got closer to Yan Yuan's computer screen.

A faint, elegant fragrance wafted into Yan Yuan's nostrils.

Her fingertips danced lightly across the keyboard as she opened Yan Yuan's code file and quickly browsed through it.

Her gaze was sharp and focused, seemingly able to penetrate the surface of the code and get straight to the core.

"Look here," Lin Jianwei pointed to a piece of nested code on the screen.

"Your parallel strategy is coarse-grained, distributing the entire path generation task equally among the processes based on the number of paths."

This is fine when the workload is uniform, but the characteristics of low-difference sequences mean that the difficulty of path generation is not uniform. Uneven distribution of sequence points can lead to some processes being overloaded.

Meanwhile, other processes are idle, causing a severe load imbalance, which is the key to your efficiency bottleneck.

Yan Yuan suddenly realized!

He had previously focused only on the algorithm itself and the amount of communication, completely ignoring the issue of load balancing.

"What should we do then?" Yan Yuan asked in a low voice.

"We could try dynamic task allocation," Lin Jianwei said, her speech slow but extremely clear.

"For example, a master-slave model can be adopted. The master process is responsible for generating low-difference sequence points and putting these points into a task pool. When the worker processes are idle, they request a point from the pool for calculation, which can automatically achieve load balancing and avoid uneven workloads."

As Lin Jianwei spoke, she quickly drew a simple architecture diagram on Yan Yuan's draft paper.

"Furthermore," she continued, "the generation of low-dispersion sequences can also be optimized. You're using Sobol sequences, right? Their generation has recursive dependencies and isn't suitable for direct parallelization."

Consider pre-generating sufficiently long sequence segments, storing them in blocks, and having each process read them as needed to reduce the overhead of real-time generation.

Alternatively, investigate low-discrepancy sequence generators that are better suited for parallel processing, such as parallel versions of Halton sequences.

"Oh, right, there's also communication overhead," Lin Jianwei pointed to another section of code.

"You're transmitting data too frequently. You could consider reducing the number of communications, such as transmitting results in batches, or using more efficient communication primitives."

Lin Jianwei used only a few words to accurately point out several key problems in Yan Yuan's code and gave clear and feasible optimization directions.

The fog that had been troubling Yan Yuan for half an hour was instantly dispelled.

"So that's how it is!" Yan Yuan suddenly understood, a relieved smile appearing on his face. "Thank you so much, senior. I really didn't think of load balancing and dynamic scheduling before."

Seeing Yan Yuan's eyes light up instantly and his sincere gratitude, Lin Jianwei's cheeks also flushed slightly.

Lin Jianwei said softly, "Actually... this problem is quite challenging. You've already done a great job. If you encounter similar problems in the future..."

She paused, then lowered her voice further.

"Actually, you can ask me through WeChat or by email. Looking up information in the library is a good way, but sometimes, this method might be a little inefficient."

Yan Yuan was taken aback, then awkwardly scratched the back of his head, his face turning even redder.

It wasn't that he didn't want to ask, but he had already assumed that Lin Jianwei didn't like chatting with him, and he didn't want to be rejected.

So even if she had questions, she preferred to figure them out herself or ask the professor, and never contacted her again.

That's what I think, but I certainly can't say it like that.

"Uh... well..." Yan Yuan made an excuse, "I've been too busy with competitions and training lately, and my time is quite fragmented. I was thinking of figuring it out on my own first, and I was also afraid of bothering you... But you're right, senior. I will definitely humbly ask for your advice when I encounter difficulties in the future."

Lin Jianwei couldn't help but smile as she looked at his embarrassed yet earnest expression.

"I won't bother you. You can ask me anytime. It's normal to have difficulties with your studies. We can only improve by communicating with each other." She picked up the stack of materials she had placed aside. "Then keep up the good work. I'm going to find a seat now."

"Okay, thank you, senior." Yan Yuan said softly.

Lin Jianwei, clutching the documents, turned and left, her figure disappearing among the bookshelves.

Yan Yuan sat there, looking at the question on the screen that had once driven him crazy, but his heart was filled with a sense of sudden enlightenment.

Those few short minutes just now.

He witnessed firsthand the true nature of Lin Jianwei beneath her aloof and mature exterior – she was a "strong person" who was professional, precise, and efficient.

Lin Jianwei's composure and wisdom were just as attractive as her appearance, and Yan Yuan gained a new understanding of her.

As Lin Jianwei walked towards her seat, the image of Yan Yuan from earlier involuntarily surfaced in her mind.

It turns out that even the "English supercar" that is almost unstoppable on the field can be embarrassed and puzzled when faced with academic problems.

This stark contrast made her impression of Yan Yuan more three-dimensional and real.

The person he was just now wasn't a star player adored by millions of fans, but a young man who also worries about his studies, humbly seeks advice, and is hardworking and genuine.

The two of them have a more comprehensive and multi-dimensional understanding of each other.

The library remained quiet, with only the soft sounds of turning pages and typing.

But in this corner, two young hearts quietly drew closer because of an algorithm problem.