Genius Girlfriend

Jiang Yubai was right—the introductory class was about to begin.

Lin Zhixia didn't want to be late. She grabbed Jiang Yubai's wrist, pulling him forward as she confided, "Jiang Yubai, something happened that's really bothering me. Would you listen?"

Jiang Yubai replied gently, "What is it? Just tell me."

Lin Zhixia glanced back at Lin Zeqiu. Her eyes held a hidden grievance, shimmering with unshed tears. But after a brief moment of eye contact, her brother turned and walked away.

From Lin Zhixia's perspective, her brother's classmates quickly caught up with him, their receding figures growing distant until they vanished at the stairwell.

In reality, Lin Zeqiu absentmindedly stepped onto the stairs, gripping the handrail. He had been about to go find Lin Zhixia when he remembered those terrifying nightmares—dreams that left him frightened out of his wits, waking with his pajamas soaked in cold sweat.

Moreover, Lin Zeqiu believed his sister was too young to understand gender boundaries, which explained her close relationship with Jiang Yubai.

How could Lin Zhixia allow a boy to hold her hand in public at school? She needed to understand one thing—in middle school, girls should play with girls, and boys with boys. Students of different genders must maintain appropriate distance.

School wasn't the right place to educate his sister.

Lin Zeqiu planned to take Lin Zhixia aside after returning home and properly teach her what was acceptable and what wasn't.

Lin Zeqiu was still thinking about Lin Zhixia.

Meanwhile, Lin Zhixia cast aside all distractions and resolutely headed toward the lecture hall.

Classes Seventeen and Eighteen had mostly arrived. Students from the two classes sat on opposite sides of the classroom. The central row of seats remained completely empty, serving as a dividing line between the two Olympiad classes.

The moment Lin Zhixia appeared, Han Peng called out, "Class Monitor Lin? Class Monitor Lin! Come sit here with Jiang Yubai! We saved seats for you!"

Lin Zhixia and Jiang Yubai walked over and took their seats.

While other students only brought notebooks, Jiang Yubai carried a heavy backpack because it contained the Competition Question Bank Lin Zhixia had given him—clearly a valuable item he decided to keep with him.

The classroom maintained discipline without supervision, with no one raising their voices.

Lin Zhixia lowered her voice and quietly told Jiang Yubai, "That senior we met in the hallway earlier, the one who's 1.8 meters tall..."

"Who is he?" Jiang Yubai asked casually.

Lin Zhixia explained honestly, "That's my brother—my biological brother from the same parents. His name is Lin Zeqiu, mine is Lin Zhixia. Obviously these are sibling names. He's autumn, I'm summer... I don't understand why he won't acknowledge our relationship. This morning he warned me not to call him 'brother' at school. He pretends not to know me in front of his classmates and treats me like just another freshman in the Olympiad class..."

A raging fire burned in Lin Zhixia's heart, consuming all other emotions and leaving only indignation in its ashes: "Why would he do this? Does he hate me? I'm so angry! We grew up together! He's always found me annoying, called me chatterbox, said I waste his time! I'm never talking to him again!""Does Lin Zeqiu often scold you?" Jiang Yubai emphasized this point.

"Not exactly," Lin Zhixia rested her chin on her hand. "I don’t know how to explain it... Oh, I’ve got it—he just speaks harshly. I remember every word he’s ever said."

Jiang Yubai thought for a moment, then rationally concluded, "Don’t blame yourself. Lin Zeqiu needs to regulate his own emotions. My dad says you shouldn’t lose your temper with family; everything can be discussed calmly within the family."

"What if discussion doesn’t work?" Lin Zhixia asked earnestly.

Jiang Yubai said calmly, "Kick him out of the house."

Lin Zhixia was stunned by Jiang Yubai’s imposing presence. She gained a whole new understanding of his father’s parenting style.

At the same time, she felt increasingly troubled and frustrated—the "kick him out" method was definitely not an option; it was too cold-blooded and terrifying. So what else could she do? She couldn’t understand Lin Zeqiu’s bizarre and peculiar thought processes at all. Were she and Lin Zeqiu going to become strangers from now on? After returning home at noon today, what attitude should she adopt toward her brother?

Jiang Yubai suggested, "If you have time, find an opportunity to talk with Lin Zeqiu."

"Talk with him?" Lin Zhixia countered. "Should I take the initiative to communicate with him?"

"Yes," Jiang Yubai affirmed.

Lin Zhixia shook her head vigorously. "No, no, no, you don’t get it..." She slumped over the desk and whispered softly, "He doesn’t recognize me now, doesn’t like me—he’d definitely be super harsh with me. I hate it when Brother is harsh with me."

Jiang Yubai tapped the desk lightly with his finger. "He might have something to say to you. Have your dad sit in on the conversation; he wouldn’t dare be harsh with you then."

"My dad is different from your dad," Lin Zhixia explained. "My dad is very gentle. My brother doesn’t hold any awe or fear toward Dad. However, Brother is very obedient at home—he sweeps, mops, washes dishes, and does laundry. Our washing machine at home is a twin-tub washer, you know, the kind with two tubs... Do you know it? One tub is for washing, the other for spin-drying."

Jiang Yubai knew nothing about household chores. His hands had never touched rough work; he had never done any dirty or tiring tasks. But he understood that Lin Zhixia’s brother contributed a lot to the family. Thinking this way, Jiang Yubai’s impression of Lin Zeqiu improved slightly.

But only slightly.

Jiang Yubai believed that, as an older brother, Lin Zeqiu should set a better example. Even if Lin Zeqiu genuinely disliked Lin Zhixia, he shouldn’t go around saying "my sister is annoying" every day.

Jiang Yubai’s father had once told his son—a mature man should be reserved and broad-minded, with vision and courage, not letting others easily guess his thoughts. It was clear that Lin Zeqiu wasn’t mature enough, and Jiang Yubai hoped he would grow.

After careful consideration, Jiang Yubai reluctantly said something positive about the brother: "Lin Zeqiu does have a sense of family responsibility."

Then, Jiang Yubai continued comforting Lin Zhixia: "When you talk to Lin Zeqiu, appeal to his emotions and reason with him. Ask him why he’s pretending not to know you."

The dean of students had already entered through the main door.

This dean appeared to be in his fifties. His hairstyle was rather distinctive—a ring of sparse hair encircled his head, with a completely bald patch in the center. Several students from Class 18 whispered among themselves and secretly gave the dean a nickname: "Mediterranean."The dean noticed the students in the front row were mocking his hairstyle, but he showed no sign of minding. He cleared his throat and spoke calmly, "Class, look up now. This introductory lecture is important—it relates to your choices over the next three years and your development path in the provincial No. 1 High School's Olympiad class. On my first slide, there's a NetEase 126 email address and password. I've uploaded the training overview and materials for the Olympiad class as attachments to that inbox. When you get home, if you have internet access, download the digital copies. The school will also provide printed versions. Make sure to read and review them regularly, alright?"

"Alright!" Lin Zhixia chimed in softly.

Lin Zhixia had just resolved her inner turmoil. Jiang Yubai's analysis and advice had been very helpful to her, and he had passed his courage on to her.

After returning home today, she would talk to her brother! Just as Jiang Yubai had said, she should give it a try first, regardless of the outcome.

Lin Zhixia silently concluded in her heart: Jiang Yubai is fearless, Jiang Yubai is logical, Jiang Yubai is knowledgeable—Jiang Yubai is indeed Lin Zhixia's eternal friend, her best friend.

He could listen to her confide, help her plan, and offer suggestions, which made her feel very secure. The emotional value he brought was always positive. In Lin Zhixia's memory, not a single action or word from Jiang Yubai had ever hurt her.

Lin Zhixia suddenly understood: "No wonder, no wonder..."

Jiang Yubai, while taking notes, asked her, "No wonder what?"

"No wonder I feel happy every time I see you," Lin Zhixia analyzed rationally and calmly. "I'm just an ordinary Deep Learning Artificial Neural Network, and my objective function is to make my life happier. When I lean toward you, I receive positive feedback—I'm bound to grow closer to you."

Jiang Yubai's handwriting was neat and fluid. He looked ahead and requested, "Lin Zhixia, please speak human language."

Lin Zhixia immediately complied: "You're really great."

Jiang Yubai's pen paused.

Lin Zhixia worried he might not understand. She emphasized again, "You're especially great. Even if there are many unattainable things in life, at least meeting you is something rare and precious. Truly, friendship between friends is priceless."

After saying this, Lin Zhixia nodded.

The page in Jiang Yubai's notebook crumpled under his grip. He lowered his head, propping up one side of the notebook to cover half his face. He thought he was contemplating the "Olympiad class training model," but what he wrote down was "friendship is priceless."

Last year at the experimental primary school, Jiang Yubai had already received the evaluation "you're super impressive."

Today, in the lecture hall of provincial No. 1 High School, Jiang Yubai heard again, "You're really great, you're especially great..." and a series of other words he was too embarrassed to recall in detail.

Perhaps Lin Zhixia was both his competitor and his true friend. These two identities weren't contradictory; instead, they motivated him to continually improve himself.

Jiang Yubai's fighting spirit was ignited.He noted down the teaching methods of the Olympiad class, the students' course selection directions, and the training programs from previous years. This weekend, he would discuss strategies with his tutoring team to quickly formulate an effective plan. He aimed to advance side by side with Lin Zhixia, sweeping through major awards at the provincial, national, and even global levels.

On the podium, the academic director stood with his hands behind his back, gazing at the many students in the Olympiad class.

The slideshow reached its final slide. This introductory lesson was nearly over. The academic director hadn’t taken up too much time. His teaching was skillful, balancing detail and brevity, leaving a deep impression on the students. One of his life principles was never to waste words on students.

The students were all watching him.

Their faces were young. One day, they would grow into pillars of the nation.

"Alright, everyone, pay attention," the academic director announced loudly. "Next, let’s give a round of applause to welcome the homeroom teachers of Class 17 and Class 18—Teacher Zhang and Teacher Wang!"

The lecture hall erupted in enthusiastic applause. The sound was immense, like surging waves crashing through the previously tranquil atmosphere.

Teacher Zhang and Teacher Wang stepped onto the podium together.

Teacher Zhang, the homeroom teacher of Class 17, bent down to operate the mouse and opened a Word document titled "Math Warm-up Quiz." The document contained forty small questions, each occupying a single page.

Teacher Wang, the homeroom teacher of Class 18, pulled out a small whiteboard. He picked up a black marker and wrote on it: Class 17, zero points. Class 18, zero points.

Teacher Wang briefly explained the rules of the competition: "Students! These are quick-response questions. A correct answer earns one point, while an incorrect answer deducts one point. If a student from one class answers incorrectly, we will randomly select another student from the opposite class."

An incorrect answer would lead to a deduction?

Hearing this unfortunate news, the students in the room became cautious. Some even decided not to participate to avoid dragging their class down, choosing to remain silent throughout. They figured it was better to stay quiet than to be the "one bad apple that spoils the whole barrel."

Teacher Zhang, the homeroom teacher of Class 17, smiled knowingly. He straightened up, displayed the first question from the Word document, and read it aloud: "What are the interior and exterior angles of a regular octagon?"

Lin Zhixia immediately raised her hand.

However, a female student from Class 18 suddenly stood up and answered directly: "The interior angle is 135 degrees, the exterior angle is 45 degrees, and the sum of the interior angles is 1080 degrees."

This female student wore glasses, had short bobbed hair, and was dressed neatly, though her appearance was unremarkable. Her tone of speech was very steady, like a calm, flowing river.

Teacher Wang gently criticized her: "Jin Baihui, you need to raise your hand first. Wait until we call on you before standing up. Respect the rules of the game..."

Teacher Zhang, however, showed leniency: "Oh? So this is Jin Baihui from Class 18? It’s fine. Jin Baihui’s mental math is very fast. Other students might not be as quick as her. Let’s go with it! Class 18 earns one point."

Why should that be?

Lin Zhixia muttered under her breath, "I can do mental math too. I’m faster than her."

Shen Fuxuan hissed softly and whispered, "Jin Baihui! That’s Jin Baihui!""Who is Jin Baihui? Is she very impressive? Her name didn't appear on the entrance exam ranking list," Lin Zhixia retorted.

"She was last year's top scorer, didn't you know?" Shen Fuxuan turned his head toward Lin Zhixia. "Jin Baihui took the provincial No.1 Middle School's junior high Olympiad class entrance exam last year. She even got admitted to a Young Talent Class in Beijing. She studied there for over half a year but couldn't adapt..."

"So Jin Baihui has returned to Provincial No.1 Middle School?" Jiang Yubai inquired.

"Yeah," Shen Fuxuan covered his mouth with one hand, secretly telling them, "The homeroom teacher of Class 18 particularly values Jin Baihui. I heard from my mom that Class 18's teacher would rather give up Lin Zhixia to Teacher Zhang than lose Jin Baihui as a student."

"Your mom? How does your mom know what Class 18's homeroom teacher thinks?" Lin Zhixia noticed this point.

Shen Fuxuan stretched out his legs, sitting like a lazy old man. He answered without reservation: "My mom is the principal of Provincial No.1 Middle School. I chose Class 17 myself. Wherever the top scorer goes, I follow. If you had gone to Class 18, I would have followed you too."

His mom is the principal of Provincial No.1 Middle School...

Then his grandmother must be Professor Shen Zhaohua?

Lin Zhixia finally connected the causal relationships, feeling extremely surprised for a moment. She had learned quite a few inside stories from Shen Fuxuan. Her attention toward Jin Baihui heightened even more.

While Lin Zhixia, Jiang Yubai, and Shen Fuxuan were chatting, Teacher Zhang announced another problem. That problem was again answered by Jin Baihui raising her hand first. Her mental calculation abilities were indeed not to be underestimated.

Class 17 was trailing by two points.

Jin Baihui glanced sideways at the students of Class 17. With her chin slightly tilted and a cold expression, she appeared thoroughly provocative.

Jin Baihui's seat was near the boundary between Classes 17 and 18. And Duan Qiyan happened to be sitting nearby.

Duan Qiyan crossed his arms and secretly glanced at Jin Baihui. Jin Baihui raised her little finger at him, nearly making him explode with anger on the spot.

All these subtle movements were noticed by Teacher Zhang.

Teacher Zhang read unhurriedly: "Third question: Given that the first five terms of an arithmetic sequence are all prime numbers, what is the minimum possible value of the fifth term?"

Jin Baihui raised her hand high.

But Lin Zhixia stood up to answer: "The minimum value of the fifth term is 5. That arithmetic sequence is 29, 23, 17, 11, 5."

Teacher Zhang said with a smile: "Lin Zhixia, you're correct, but you need to raise your hand first."

Lin Zhixia perfunctorily admitted her mistake: "Sorry, teacher, I was too eager. Next time I'll raise my hand."

Teacher Wang smoothed things over: "You're Lin Zhixia from Class 17? Not bad, not bad. Although I didn't interview you, other teachers all speak highly of you. We look forward to you bringing honor to Provincial No.1 Middle School. Okay! Class 17 gains one point. After this round, everyone must raise their hands! We must respect the rules, alright?"

All the students responded in unison.

Teacher Zhang scrolled the mouse wheel, and Teacher Wang read the fourth question for everyone: "Students, please listen: Assume n is a single-digit number in base-10. There exists another three-digit number in base-10. This three-digit number is represented as nq in Base-58 and as (n-1)g in Base-62. What is this three-digit number?"

Jiang Yubai was the first to raise his hand.Lin Zhixia noticed his movement and stopped competing with him. She began to worry whether Jiang Yubai could answer correctly. Holding her breath, she heard Jiang Yubai say, "The three-digit number is 512, and n equals 9."

Lin Zhixia extended both index fingers, pressing their tips together repeatedly, quietly applauding for him.

Teacher Zhang praised happily, "Excellent! Quick and accurate! Class Seventeen gains another point! Teacher Wang and I were initially concerned that the questions might be too difficult to engage everyone, but now it seems students from both classes are thoroughly enjoying themselves! Great! Keep it up!"

Han Peng, sitting in front of Lin Zhixia, couldn't help muttering, "I'm speechless... So far, only Jin Baihui, Lin Zhixia, and Jiang Yubai have answered questions, yet Teacher Zhang thinks we're all having fun."

Leaning back in his chair, Han Peng tilted his head backward and asked Jiang Yubai, "How did you solve that last question?"

"Rapid base conversion," Jiang Yubai replied unexpectedly, "It's quite fundamental."

Jiang Yubai had learned base conversion two years ago and had spent the last six months intensively practicing mental and oral arithmetic. Even though he played throughout the entire summer vacation, he maintained his mathematical proficiency.

"That's right, Jiang Yubai is correct. That kind of conversion is relatively basic," Lin Zhixia particularly agreed with him.

Han Peng stretched his neck forward, nearly choking. Supporting himself on the desk, he sat up properly again, lowered his head, and coughed violently.

Life is really tough, Han Peng thought to himself.

Meanwhile, the competition continued. Lin Zhixia gradually felt it was unfair. She was always the first to raise her hand. However, sometimes Teacher Wang wouldn't call on her, preferring to call out "Jin Baihui" instead. The math warm-up questions for seventh graders weren't particularly difficult, with almost no especially complex concepts, so it wasn't surprising that Jin Baihui could solve them.

"Can an unfair competition even be called a competition?" Lin Zhixia wondered.

Jiang Yubai had already seen through everything. He enlightened Lin Zhixia: "The dean is sitting at the back of the classroom. Teacher Wang can't let the dean think Class Eighteen is far inferior to Class Seventeen. When you and Jin Baihui raised your hands consecutively, there was only a two-second gap—not very noticeable. Also, if Class Eighteen loses too badly, it would severely damage their morale and hinder their confidence building."

Lin Zhixia slumped over her desk. She unilaterally withdrew from the competition, expressing silent protest.

Her cheek pressed tightly against her arm, making her appear both pitiful and adorable.

Noticing Lin Zhixia's state, Jiang Yubai felt a strong sense of mission welling up inside him. He realized Teacher Wang was intentionally ignoring Lin Zhixia—equivalent to a basketball referee showing bias by restraining the opposing team's key player.

He had seen this kind of plot in "Slam Dunk."

Undaunted, he remained calm and composed.

Teacher Wang continued reading the question: "When throwing a die, accumulate the points shown. If the total exceeds 10,000, it counts as failure. If it equals exactly 10,000, it counts as success. If it's less than 10,000, continue throwing the die. What is the probability of success?"

The classroom fell silent for over ten seconds before Jiang Yubai and Jin Baihui simultaneously raised their hands.

Before Teacher Wang could speak, the dean sitting in the last row said, "I see these two students raised their hands almost simultaneously. Let them both answer. Today's event is just a small competition, not a major contest. Friendship first, competition second."Teacher Wang first asked Jiang Yubai, "What's the probability?"

Jiang Yubai calmly replied, "Two-sevenths."

Jin Baihui suddenly spoke up, questioning Jiang Yubai, "How did you calculate it? Your method isn't as fast as mine. I can set up an equation to get the result of two-sevenths."

Teacher Wang nodded repeatedly, "What equation? Jin Baihui, come up to the blackboard and show everyone."

Jin Baihui's face was covered with a layer of frost, a blend of chilliness and arrogance. She cared more about winning and losing than Jiang Yubai. She wrote on the blackboard: "When throwing a dice six times, the expected value is 3.5. I'll first use a formula to prove the sequence can eventually converge..." Realizing her logic wasn't rigorous enough, she immediately applied L'Hôpital's rule.

Just as Jin Baihui was about to state her conclusion, Lin Zhixia's ethereal voice drifted over: "This problem isn't difficult. I believe you can solve it quickly. But I think you don't need to write out the general term formula. There's a scenario called the 'lattice case' in Blackwell's key renewal theorem, and the dice game perfectly fits its constraints. In this case, each term of the random variable can be expressed as a constant divided by the expected value. The constant for the dice game is 1, so the result is 1 divided by 3.5, which equals two-sevenths."

Jiang Yubai remained silent.

Because his method was the most elementary.

He assumed the probability of success was p, the probability of failure was (1-p), and all failure scenarios could be exhaustively listed. For example, one scenario would be when the cumulative dice points reached 9995, rolling any number other than 5 would mean losing... Continuing this reasoning, he could still calculate the answer.

Both Jin Baihui and Lin Zhixia employed mathematical theorems far more complex than his.

Yet Teacher Zhang said: "Jin Baihui's algorithm is very rigorous, demonstrating solid mastery of advanced mathematics concepts. I also appreciate Jiang Yubai and Lin Zhixia's approaches - Blackwell's renewal theorem is concise and powerful."

Lin Zhixia nodded proudly.

Sitting at her desk, she secretly extended a hand downward. Jiang Yubai mimicked her gesture, and she seized the opportunity to immediately high-five him.

Jiang Yubai felt greatly encouraged. He lowered his head and smiled silently.