6 articles
Master bit manipulation for FAANG interviews: XOR tricks, popcount, bitmask DP, Brian Kernighan, two-complement identities, and 5-language operator reference with full problem index.
LeetCode 78 Subsets: enumerate the power set with bitmask iteration. Master the elegant 2^n bit-loop FAANG interviewers prefer over recursion for its clarity and speed.
LeetCode 1178 Number of Valid Words for Each Puzzle — count words containing the puzzle’s first letter using only puzzle letters. The 26-bit bitmask plus the (sub - 1) AND parent submask trick crushes a brute-force quadratic solution.
LeetCode 318 Maximum Product of Word Lengths — find two words sharing no letters with maximum length product. Encode each word as a 26-bit set, then check disjointness with one bitwise AND. The textbook FAANG bitmask interview problem.
Complete bit manipulation cheatsheet for FAANG interviews: all critical tricks, bitmask DP patterns, XOR properties, complexity table, and full problem index across 18 problems.
Bit manipulation is the cheat code of competitive programming and tier-1 interviews. Master the XOR identities, n & (n-1) tricks, subset enumeration over a bitmask, and bitmask DP techniques that turn O(2^n) brute force into elegant constant-factor wins.