7-Day Puzzle a Day Streak
Solve one small logic or coding puzzle each day and note the steps you used. Check in daily.
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Coding · Facts & stats · iChallenge network
Daily facts and stats about algorithms, sorting, searching and efficiency, plus real challenges to put them to work.
What does Dijkstra's algorithm find?
Dijkstra's algorithm finds the shortest paths from a starting node when edge weights are not negative.

One ranked attempt per day. Practice as much as you like.
Join one, log your days or post your proof. Finishing earns XP and the Finisher badge.
Solve one small logic or coding puzzle each day and note the steps you used. Check in daily.
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Sort a shuffled suit of playing cards using a method you name, like insertion sort, and count the moves. Post a write-up.
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Write clear numbered steps for an everyday task, like making tea, that a stranger could follow. Share it.
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Live counts from AlgorithmChallenge.com. All arena stats →
Earned on any arena, shown on your profile everywhere.
Add your email to keep your level, streak and badges if you switch devices, and carry them to every iChallenge arena. One email when you save; no spam.
Fund a prize on AlgorithmChallenge.com and your brand sits on the challenge card, the leaderboard and every finisher's share. Prizes only appear once they're funded, so players can trust what they see.
Any language. Challenges score consistency and completion, not syntax.
Yes — quiz rounds start easy and scale with your streak.
Everyone on this arena gets the same five questions each day, from easy to hard. You get one ranked attempt; practice rounds are unlimited.
100 points per correct answer, up to 50 more for answering quickly, a combo multiplier for answers in a row, and 150 bonus points for a perfect round.
Yes. Playing, streaks, badges and leaderboards are free. Some challenges carry a sponsor-funded prize; the challenge card shows it when one is funded.