1582 articles
Master the computational geometry primitives every interviewer expects: cross product orientation, segment intersection, Graham scan convex hull, polygon area via shoelace, and point in polygon.
Master combinatorial game theory: Nim XOR strategy, Grundy numbers, Sprague-Grundy theorem, mex, and minimax DP for stone games and impartial games in competitive programming and interviews.
Master randomized algorithms in interviews: reservoir sampling for streams, quickselect for O(n) kth element, Fisher-Yates shuffle, and Bloom filters with probability proofs.
Apply the inclusion-exclusion principle to divisibility counting, derangements, Euler totient, and surjection problems. The single most useful tool for combinatorial counting in interviews and competitive programming.
Complete reference for math and number theory DSA patterns: algorithm selection guide, complexity table, template library, and top 25 interview problems ranked by FAANG frequency.