I am a postdoc associate in the Theory of Distributed Systems group at MIT, supervised by Nancy Lynch.

Before coming to MIT in September 2015, I obtained my Ph.D. from University of Michigan.

My thesis advisor was Seth Pettie. My thesis, Algorithms for Fundamental Problems in Computer Networks,

has received The 2016 Principle of Distributed Computing Dissertation Award for contributions

to fundamental problems in distributed graph algorithms (a.k.a. network algorithms).

My research is in using theoretical tools to solve problems from distributed settings, such as problems

arising from large-scale distributed networks and biological systems. One of most fundamental problems

is the coloring problems in the distributed setting, where we have made interesting progress.

Also, I am interested in developing more efficient algorithms for classic combinatorial optimization problems

such as matchings and minimum cuts in both distributed and centralized settings.

See my [research statement] for more details.

**Distributed Degree Splitting, Edge Coloring, and Orientations**

Mohsen Ghaffari and Hsin-Hao Su

SODA 2017 [arXiv:1608.03220]

The key contribution: The first deterministic poly-logarithmic rounds O(**Δ**)-edge-coloring algorithm (to be more precise (2+eps)**Δ).**

**Scaling Algorithms for Weighted Matching in General Graphs**

Ran Duan, Seth Pettie, and Hsin-Hao Su

SODA 2017 [arXiv:1411.1919v4]

The key contribution: Weight matching in O(mn^{½}log (nW) ) time for general graphs. Previously the bound was only known for bipartite graphs.

**Ant-Inspired Density Estimation via Random Walks**

Cameron Musco, Hsin-Hao Su, and Nancy Lynch

PODC 2016 [arXv: 1603.02981][Press Coverage: MIT News]

The key contribution: Density estimation via random walk sampling works well even in graphs with low expansions (e.g. 2D torus).

**Clairvoyant Mechanism for Online Auctions**

Philipp Brandes, Zengfeng Huang, Hsin-Hao Su, and Roger Wattenhofer

COCOON 2016

**Distributed (Δ+1)-coloring in Sublogarithmic Rounds**

David G. Harris, Johannes Schneider, and Hsin-Hao Su

STOC 2016 [arXv: 1603.01486]

The key contribution: The first sub-logarithmic rounds (**Δ**+1)-coloring algorithm**.**(

The separation between two of the most fundamental problems-The maximal independent set problem and the**Δ**+1)-coloring problem.

**Brief Announcement: Distributed Task Allocation in Ant Colonies**

Anna Dornhaus, Nancy Lynch, Tsvetomira Radeva, and Hsin-Hao Su

DISC 2015

**(2Δ-1)-Edge-Coloring is Much Easier than Maximal Matching in the Distributed Setting**

Michael Elkin, Seth Pettie, and Hsin-Hao Su

SODA 2015

The key contribution: Very efficient algorithms for (1+eps)**Δ-edge-coloring and coloring in locally-sparse graphs.**

**The separation between two fundamental problems-The maximal maximal problem and the**(2**Δ**-1)-edge-coloring problem.

**Almost-Tight Distributed Minimum Cut Algorithms**

Danupon Nanongkai and Hsin-Hao Su

DISC 2014 [arXv: 1408.0557]

Preliminary versions appear as brief announcements at SPAA 2014 and PODC 2014

The key contribution: Distributed minimum cut algorithms for (1+eps)-minimum cut in Õ(D+n

^{½}) rounds in CONGEST model, which is essentially tight.

**Distributed Algorithms for the Lovasz Local Lemma and Graph Coloring**

Kai-Min Chung, Seth Pettie, and Hsin-Hao Su

PODC 2014

The key contribution: Efficient constructive algorithms for Lovasz Local Lemma and their applications in the coloring problems.

**Fast Distributed Coloring Algorithms for Triangle-Free Graphs**

Seth Pettie and Hsin-Hao Su

ICALP 2013

Invited to ICALP 2013's special issue of Information and Computation [pdf]

The key contribution: Improving the chromatic number for triangle-free graphs to (4+o(1))Δ/log Δ (Previously it was 160Δ/logΔ).

Also gave efficient distributed algorithms to construct the coloring.

**A Scaling Algorithm for Maximum Weight Matching in Bipartite Graphs**

Ran Duan and Hsin-Hao Su

SODA 2012 [pdf][slides]

The key contribution: The first algorithm for Maximum Weight Matching that performs strictly better than O(mn^{½}log (nW) ).

**Efficient Algorithms for the Problems of Enumerating Cuts by Non-decreasing Weights**

Li-Pu Yeh, Biing-Feng Wang, and Hsin-Hao Su

Algorithmica, 56 (2010) 297-312. [pdf]

**An Improved Algorithm for Finding a Length-Constrained Maximum-Density Subtree in a Tree**

Hsin-Hao Su, Chin Lung Lu, and Chuan Yi Tang

Information Processing Letters, 109 (2008) 161-164. [pdf]