Code champions: How UW–Madison built a programming dynasty

By Karen Barrett-Wilt

One of the winningest teams at UW-Madison is not a sports team.

A winning tradition

For the seventh consecutive year, a UW-Madison team has claimed first place at the regional round of the International Collegiate Programming Contest (ICPC). The numbers tell an extraordinary story. Five of UW-Madison's teams placed in the top 10 at regionals, and eight in the top 20. The university is also tied with MIT for the ICPC's North American record, with both having 21 consecutive appearances at the World Finals.

Hosted at Epic's Verona campus in November, 16 of the 86 teams in the region competed for a chance to move on to the North American competition in March. After five hours of competition, UW-Madison team B-Tree - Tan Bui, Ishan Joshi, Tuan Tai Nguyen - solved all eleven problems in under four hours (out of five hours allotted) to claim victory. In doing so, they also protected UW's 25-year streak of advancing to the next level of competition - a record unmatched by any other institution in North America.

The architect behind the success: Dieter van Melkebeek

At the heart of this dynasty stands Computer Sciences Professor Dieter van Melkebeek, who has coached UW-Madison's ICPC teams for all 25 years. His journey began almost by accident in 2001, his first year at UW-Madison, when a graduate student from China organized a team and asked Professor Somesh Jha to coach. Van Melkebeek volunteered to help with training, delivering a few lectures on problem-solving strategies.

That first team advanced to the World Finals. Sometime after that, while reading a University of Chicago alumni newsletter, van Melkebeek came across something that surprised him: Jha announced him as his successor for the UW-Madison ICPC team. He's been there ever since, building what Jha describes as "an ecosystem for these teams to thrive."

Van Melkebeek's approach combines rigorous training with genuine care for his students. Each fall, he runs a weekly ICPC in-person training session, where students tackle challenging problems, develop team strategies, and learn to work together under pressure. "These are very motivated students," he says. "It's a lot of work if you want to do well."

It's no easy lift for van Melkebeek, either. During the 2021 Dhaka World Finals (postponed until 2022 due to the pandemic), when student Dung Viet Bui faced visa issues that would prevent his return to the U.S., van Melkebeek negotiated with the ICPC president to allow an unprecedented substitution. When two team members graduated and moved away before the 2022 World Finals in Luxor, Egypt (which took place in 2024 after repeated postponements), he helped navigate visa complications and kept the team practicing for nearly two years.

For his 20-plus years of bringing teams to World Finals, van Melkebeek received a Lifetime Coach Award in Luxor. Despite being offered leadership positions within ICPC, he has routinely declined, saying, "I would miss the prerogative, excitement, and satisfaction of working with such super-motivated and interested students!" His commitment runs so deep that he continued coaching even while on sabbatical, when faculty typically pause all departmental activities.

From bronze aspirations to silver medals

The 2022 World Finals in Luxor marked a watershed moment. Team members Nitit Jongsawatsataporn, Mingrui Liu, and Ziyi Zhang entered the five-hour competition expecting to compete for bronze. But their strategic pivot in the final minutes allowed them to solve one last problem with just eight minutes remaining, catapulting them to a silver medal - and UW-Madison to its first-ever ICPC World Finals medal.

"We didn't know until the announcement of the results that this was the decisive problem, so our success was a delightful surprise," said Zhang. They finished behind only MIT among North American teams, a remarkable achievement considering many competing teams include students who train full-time for competitions. In fact, particularly in other countries, many team members are functionally full-time competitors - they're recruited by universities specifically for their ICPC skills, they register for classes they don't attend, and they travel from competition to competition.

Though Wisconsin may be a bit of an underdog internationally, van Melkebeek says the Badgers have a strong reputation within ICPC. (After all, the third-place team at this year's regional competition was named Mad-is-sun, despite being from the University of Minnesota.) Van Melkebeek takes particular pride that two team members, Nitit and Ziyi, "received their entire undergraduate education here and developed their ICPC prowess up to that level through our training program," rather than coming to UW with previous ICPC experience. It's a testament to the quality of training at UW-Madison, where students balance competitive programming with their coursework and other activities.

A culture of mentorship

Perhaps van Melkebeek's most lasting contribution is the culture of mentorship he's cultivated. Former team members regularly return to help train newer competitors. Before winning second place at the World Finals, Zhang stayed connected to the club during the pandemic by coaching teams remotely from China. He trained the ICPC team at the University of Chicago until he graduated last year. This year, students from past teams are leading many of the training sessions, perpetuating the knowledge and passion that van Melkebeek has instilled.

One of those students is Harry Huang x'27, a transfer student who came to UW-Madison in the spring of 2024. An ICPC competitor since high school, Huang was a member of the only team (out of 96) at the 2024 regional competition that solved all the problems. This semester he led seven of the ten training sessions for the current teams and says that as a teacher/mentor, you can't simply base solutions you come up with on your own intuition. You need to "look deep inside every aspect of a problem and examine your assumptions so you can clearly explain how you would solve the problem." The students benefit from his expertise, and he comes away with a deeper understanding of how he develops solutions.

Looking ahead

Epic Systems has been hosting the regional competition at their Verona campus and providing crucial support over the past 15 years, and UW-Madison is fielding more teams than ever before. As B-Tree prepares for the North America Championship in March, aiming to match or surpass the 2022 silver medal performance, they carry forward a 25-year legacy of excellence - and the unwavering support of a coach who has dedicated more than a quarter century to their success.

The regional results

UW-Madison teams took five places of the top ten in the regional competition, and all ten UW-Madison teams placed comfortably in the top half. Team Ichikawa Zenith solved five of the 11 problems faster than any other team in the region, and nine of the problems faster than team B-Tree. Team Ichikawa Zenith missed an output formatting requirement for Problem J and had 26 unsuccessful attempts at that problem, resulting in second place for the team. "Ichikawa Zenith is the team we were expecting to advance as they are of the caliber that won a silver medal at the 2022 World Finals," explained van Melkebeek, noting that issues with Problem C - where their correct solution was initially rejected - may have exhausted the team and affected their later performance.

Final team standings:

• B-Tree (1st place, all 11 solved): Tan Bui, Ishan Joshi, Tuan Tai Nguyen
• Ichikawa Zenith (2nd place, 10 solved): Yanpeng Wei, Frank Xiang, Xusheng Zhi
• Mini Soda (4th place, 10 solved): Guanlin Chen, Xinchen Shen, Enze Zhang
• Master Debaters (6th place, 9 solved): Vince Cimino, HuaiYuan Jing, Merlin Morton
• Divide and Surrender (8th place, 8 solved): Brandon Han, Albert Wu, Karis Zhuang
• 52 Attempts, 2 Answered (12th place, 8 solved): Patrick Decabooter, Kushal Rao, Austin Tsai
• Brute Force (15th place, 7 solved): Minh Bui, Nghia Nguyen, Ti Wu
• badgerz (20th place, 6 solved): Pranav Avadhanam, Connor Simms, Samad Syed
• goldMedal (27th place, 5 solved): Arshjeet Singh Bajwa, Osmond Lin, Jianhong Shi
• I(Can)tProgramCorrectly (28th place, 5 solved): Gil Friedman, Anna Sun, Kevin Wang

Full scoreboard at https://ncna25.kattis.com/contests/ncna25/standings