AAC
Complete the line
The algorithm is done except for one line. Pick it from four nearly identical candidates.
i < n │ i <= n
13 PROBLEMS · 5 HOURS · ONE SCOREBOARD — NOW IN 3 MINUTES
Reduce the complexity of your solutions.
Algorithms, DevOps and AI engineering practice with the grammar of a programming contest: problems by letter, a balloon per color, a scoreboard that freezes in the last hour.
COMING TO THE APP STORE · ANDROID ON THE WAY
THE SESSION
Three lives, clock running, four formats.
No blank editor on a phone. Each question isolates one decision — the right line, the bug, the complexity — and fits in a bus queue.
BWA
Find the bug
Six lines, one wrong. Tap the line that breaks on the edge case.
for (i = 0; i <= n; i++) ← here
CTLE
Match the complexity
Drag each snippet to the right notation. The clock is ticking.
two nested loops → O(n²)
DAC
Dry run
Run it in your head and say what comes out. No compiling, no print.
output: [1, 3, 3, 7]
Fell for a classic trap — off-by-one, overflow in mid, visited marked too late — and the app explains why before the next question.
TRACKS
The curriculum is a graph. You see the edges.
Each technique is a balloon; each prerequisite, a string. A technique only opens after the ones it builds on — and the map shows why.
- Algorithms and data structuressearch, graphs, DP, heaps
- DevOpsinfrastructure, cloud, delivery pipelines
- AI engineeringautonomous agents, LLMs
SCOREBOARD
It freezes in the last hour. As it should.
Penalty added up like in a real contest: every wrong attempt costs 20 minutes. In the last hour the scoreboard freezes, and the result only shows up at the reveal.
| # | TEAM | AC | PEN | A | B | C | D | E | F | G |
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Big Theta | 6 | 412 | +12 | +31 | +158 | +74 | ?frz | +2141 | +166 |
| 2 | Off by One | 5 | 388 | +9 | +40 | +77 | +3119 | ?frz | +173 | |
| 3 | you | 5 | 402 | +14 | +136 | +63 | ?frz | +128 | +2180 | |
| 4 | Segfault | 4 | 301 | +22 | +49 | −2 | +98 | ?frz | +1190 | |
| 5 | Mod 1e9+7 | 3 | 244 | +18 | −3 | +71 | ?frz | +203 |
OPEN SOURCE
The whole app is on GitHub. Only the questions stay in the drawer.
Core, clients and backend are open to read, fork and send PRs. The only closed piece is the track content — publishing the answer key would spoil the contest.
COREOPEN
Rust + Crux
Game rules, scoreboard and offline sync in a single core.
iOSOPEN
SwiftUI
Native client on top of the core.
ANDROIDSOON
Jetpack Compose
Same core, same design system.
BACKENDOPEN
Go + PostgreSQL
Accounts, standings and synced events.
git clone github.com/josecleiton/logn
open on GitHub
Your first balloon is three minutes away.
Coming soon to theApp StoreCOMING TO THE APP STORE · ANDROID ON THE WAY