Another night of competitive programming began in Boelter Hall 3760, and soon a familiar ID appeared at the top of the leaderboard on the screen. It was MatRush.
The leaderboard displayed the real-time standing of students’ ranks as they completed each practice problem at the weekly training session. The UCLA chapter of Association for Computing Machinery, or ACM, held the regular events to mimic real competitions in preparation for the ACM International Collegiate Programming Contest.
The username MatRush belongs to Chaoshuai Lu, a UCLA graduate student in computer science. Lu attended the training sessions until they ended recently, and his team, which included two students from Peking University, placed second at the ACM-ICPC Southern California regionals last month.
“Chaoshuai is one of our best,” said Shahid Chohan, a fourth-year computer science student who leads the ACM-ICPC training sessions.
Chohan said that Lu continued to help students new to ICPC at the training sessions at Boelter Hall even after he finished the Southern California regionals.
Jian Gong, a graduate student in computer science who has been to several hackathons with Lu, said Lu also collaborates with other coders by sharing algorithms and explaining them in detail during sessions.
The history of the name MatRush goes back to Lu’s first year in college, when he decided to base his ID after that of a famous coder whom he admires, ACRush. He said he added the first three letters from the word “matrix” because he liked solving matrix problems at that time.
Lu’s competition career goes back to when he first started coding in high school in Zhejiang, China. He said he was lucky enough to meet a teacher who exposed him to coding and was willing to teach him.
“When I first tried coding, I felt like I had control over it,” he said.
From high school programming olympiads, Lu climbed his way up to placing 36th at the ACM-ICPC 2012 World Finals, where his team represented his college, Zhejiang University of Technology, among 112 colleges.
In early October, Lu finished fifth with a perfect score at the Back2School CodeSprint, organized by HackerRank, a company that exposes top coders to recruiters.
He said he is satisfied with the results, and he was excited to be near the top of the leaderboard out of a pool of about 600 college contestants.
In November, Lu made his second and last attempt to proceed to the ACM-ICPC World Finals by competing in the Southern California regionals. Lu’s team placed second and lost a spot in the finals to USC.
Chohan said he thinks it is interesting that Chaoshuai had experience in ICPC as an undergraduate student, because it is not as popular for undergraduates in the United States to do competitive programming.
Though Lu mainly practiced coding for complex mathematical problems when he was in China, he said he prefers programming that solves real-world problems.
Lu said he thinks programming education that focuses on solving problems is more useful in the workplace than competitive programming.
For example, Facebook is currently using the data infrastructure that Lu built during his internship, which helps monitor systems for debugging, he said. After he graduates this quarter, Lu said he is going to start work at Facebook in February as a software engineer.
Lu said he plans to continue doing some online competitions on HackerRank to keep his memory in good form with algorithms, but he does not plan to participate in many more large competitions in the near future because they are too time-consuming.