Xinkai Shu

Previously, I was a postdoctoral researcher at the Max Planck Institute for Informatics, hosted by Danupon Nanongkai. Before that, I received my PhD in Computer Science from The University of Hong Kong, where I was very fortunate to be supervised by Zhiyi Huang. I completed my undergraduate studies in the Yao Class, Tsinghua University.

My research mainly focuses on online algorithms beyond worst-case analysis, including algorithms with predictions and stochastic input models. Much of my work concerns matching, selection, and resource allocation problems arising in online decision making. I also study fast algorithms for shortest path problems.

Email: varepsilonshu [at] gmail [dot] com

Selected Publications

  1. Breaking the Sorting Barrier for Directed Single-Source Shortest Paths
    Ran Duan, Jiayi Mao, Xiao Mao, Xinkai Shu, and Longhui Yin
    In Proceedings of the 57th Annual ACM Symposium on Theory of Computing (STOC 2025), Prague, Czech Republic, Jun 2025
    Best Paper Award. Invited to the Journal of the ACM
  2. A Randomized Algorithm for Single-Source Shortest Path on Undirected Real-Weighted Graphs
    Ran Duan, Jiayi Mao, Xinkai Shu, and Longhui Yin
    In Proceedings of the 64th IEEE Symposium on Foundations of Computer Science (FOCS 2023), Santa Cruz, USA, Nov 2023
  3. The Power of Multiple Choices in Online Stochastic Matching
    Zhiyi Huang, Xinkai Shu, and Shuyi Yan
    In Proceedings of the 54th Annual ACM Symposium on Theory of Computing (STOC 2022), Rome, Italy, Jun 2022
  4. Online Stochastic Matching, Poisson Arrivals, and the Natural Linear Program
    Zhiyi Huang and Xinkai Shu
    In Proceedings of the 53rd Annual ACM Symposium on Theory of Computing (STOC 2021), Rome, Italy (virtually), Jun 2021

News

Jul 2026 I left the Max Planck Institute for Informatics on July 29. Many thanks to everyone there for a wonderful experience!
Apr 2026 Our paper A Faster Directed Single-Source Shortest Path Algorithm (joint work with Ran Duan, Xiao Mao, and Longhui Yin) was accepted to ICALP 2026.
Jul 2025 I gave a talk on Breaking the Sorting Barrier for Directed Single-Source Shortest Paths at IJTCS-FAW 2025.