Theory of Problem Solving

Deconstructions of algorithms and competitive programming problems — from the ICPC, IOI, Codeforces, USACO, TopCoder, and beyond. Not just the answers: each editorial reconstructs the full path to a solution — the initial observations, the ideas that failed, and the insight that finally worked.

I'm a 2× World Finalist at the International Collegiate Programming Contest, representing the University of Waterloo in 2013 (St. Petersburg) and 2015 (Morocco) — where we finished 13th in the world, 3rd in North America, and 1st in Canada — and a 2× ICPC World Finals Judge.

How I solve problems →

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StatusTitleJudgeRoundIndexStatement
Aladdin And The Return JourneyLightOJProblem Set1348[URL]
CamelotUSACOTraining-SetSection 3.3[URL]
ClosestRabbitTopCoderSRM 636 (Div. 1)500 Pt[URL]
CompartmentsCodeforcesRound #207 (Div. 1)Problem C[URL]
Cooking The BooksFB Hacker Cup2015 Qualification RoundProblem A[URL]
Dreamoon And StringsCodeforcesRound #272 (Div. 1)C[URL]
Dreamoon And SumsCodeforcesRound #272 (Div. 1)A[URL]
Free MarketCodeforcesRound #213 (Div. 1)Problem B[URL]
GhdCodeforcesRound #213 (Div. 1)D[URL]
Jeff And BracketsCodeforcesRound #204 (Div. 1)C[URL]
KitayutaMartTopCoderSRM 648 (Div. 1)550[URL]
Ksenia And CombinatoricsCodeforcesRound #224 (Div. 2)Problem E[URL]
Laser MazeFB Hacker Cup2015 Qualification RoundProblem C[URL]
Levko And StringsCodeforcesRound #210 (Div. 1)Problem C[URL]
New Years ResolutionFB Hacker Cup2015 Qualification RoundProblem B[URL]
PaperAndPaintTopCoderSRM 441 (Div. 1)1000[URL]
Set MultiplesTopCoderSRM 505 (Div. 1)500 Pt[URL]
Table DecorationsCodeforcesRound #273 (Div. 2)C[URL]
ABC-StringsCodeChefMarch 2014 Cook-OffABCSTR[URL]
Alice and BobCodeforcesRound #201 (Div. 2)C[URL]
AntichainCodeforcesRound #205 (Div. 2)E[URL]
AntimatterCodeforcesRound #225 (Div. 1)D[URL]
Beautiful SetCodeforcesRound #213 (Div. 1)C[URL]
Beef McNuggetsUSACOTraining Chapter 4nuggets[URL]
BigOTopCoderSRM 608 (Div. 1)500
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