How to play

Snippet Sprint about 5–8 minutes

5 small Python tasks that get harder as you go: 60 seconds for warm-ups, 90 for standard prompts and 120 for the tricky last one. You get some variables, like words = ["tuna", "eel", "tuna"], and a target to build, like counts. Each prompt opens with 10 seconds to read it; then the editor appears and the clock starts. Write the code, press Cmd/Ctrl+Enter, and retry as often as you like before the clock runs out. When it hits zero, whatever is in the editor runs one last time.

Any correct answer scores. How much depends on how you wrote it: each prompt has a ranked list of approaches, from the idiom an experienced Pythonista reaches for down to the slow or long-winded way.

• Leviathan+100The best way to write it.
• Trench+85Clean and idiomatic.
• Drop-off+60Good. One idiom away from great.
• Reef+35Solid, if long-winded.
• Shallows+20Correct, with a costly shortcut.
• Surface+10Works, but there's a much better way.

Near miss+20 Close isn't nothing. If time runs out (or you bank it) and your closest attempt was at least 50% right across the hidden cases, it scores a near miss: up to 50% of the tier your approach was heading for, scaled by how close you got.

Stuck? The Hint button names the tool to reach for. A prompt solved with a hint keeps 75% of its points.

Already imported for you: Counter, defaultdict, deque, OrderedDict, collections, itertools, functools, heapq, math, bisect, re, string, operator. Wrong answers that aren't close, and give-ups with nothing close, score 0. After each prompt you see the deepest way to write it.

The Deep Dive about 20 minutes

One original coding problem a day, solved right in the browser in JavaScript or Python. “Run examples” checks the examples; “Submit” runs the full hidden test suite. Your best submission counts, and partial credit is given for each test you pass.

Difficulty follows the week: Easy on Monday and Tuesday, Medium Wednesday through Friday, Hard on weekends.

Going deeper

A perfect sprint reaches 7,000 m. Solving the Deep Dive adds up to 3,935 m, and only both together reach Challenger Deep at 10,935 m. Depth resets every day.

Sunlight

0 m+

Twilight

200 m+

Midnight

1,000 m+

Abyss

4,000 m+

Hadal

6,000 m+

Challenger Deep

10,935 m+

Streaks, archive and unlimited

Finishing the sprint on its day keeps your streak going. Your history stays in this browser; no account needed. The archive has every past dive, and unlimited serves endless practice snippets.