I work with high-school students who want to take USACO seriously. We build a plan together: weekly sessions, homework that names its problem, and results tracked problem by problem. Inside that plan, every session starts from your actual stuck moments. The demos on this page are the real labs we use, and they're yours to poke.
Every lab is a real past contest problem rebuilt as something you can push on: drag the input, break it, watch the algorithm answer back - then replay the intended solution one forced step at a time. Each demo below is a lab's actual stage, driving itself until you touch it. No account, no setup.
Labs are for problems; walkthroughs are for techniques. Each one builds a technique from scratch with live widgets embedded mid-explanation - and ends with the contest problems it cracks. On the right: the widget at the heart of prefix sums, lifted straight out of its walkthrough.
Every session runs on a live shared board - we both draw at once. But a clean 9-node trie costs three minutes by hand and three seconds by generator: type the input, get the figure, spend the minutes on the thinking. And because the board knows what it drew, the figure carries its own runners: step a sort through that array, flood BFS layers across that graph, pop that heap - animated on the drawing, not narrated beside it. Boards are saved and linked from that week's session notes, so "the picture from Tuesday" is never lost.
Seven lines of indented text become the call tree; then the run plays through it, pushing and popping the call stack and filling the memo table as repeats are found.
Every student has a dashboard. Homework hangs off the session it came from, with a status and a note on how it went. Contest results sit problem by problem. LeetCode solves sync in, with a paste-import for the history sync can't see. So "how is it going?" has an answer you can open, and parents see the same view, plus a printable weekly report.
| contest | p1 | p2 | p3 |
|---|---|---|---|
USACO Dec 2025 Silver | AC 12:40 | 6/10 upsolved | WA · |
USACO Jan 2026 Silver | AC 08:12 | AC 41:03 | 8/10 drill set |
USACO Feb 2026 Silver | AC 22:05 | TLE upsolve next | - · |