10 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.
LC 136 Single Number is the canonical XOR interview problem. Every duplicate cancels itself via a^a=0, leaving only the unique element. Master this identity and every follow-up variant before your next coding screen.
LeetCode 260 Single Number III: every element appears twice except two unique elements. Master the XOR partition trick used by FAANG interviewers to test deep bitwise reasoning.
LeetCode 268 Missing Number: find the one missing integer in [0..n] using XOR cancellation or the Gauss arithmetic-series formula. Two O(n) techniques every FAANG interviewer expects you to compare.
LeetCode 477 Total Hamming Distance: sum bit-differences across every pair in linear time. Master the per-bit contribution trick that turns O(n^2) brute force into O(n) — a FAANG favorite.
LeetCode 89 Gray Code — generate an n-bit sequence where consecutive numbers differ by exactly one bit. The one-line XOR formula gray(i) = i XOR (i shifted right by 1) cracks it. FAANG-favorite bit manipulation 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.
LeetCode 421 — find the maximum XOR pair in an array of integers in O(N times 32) using a binary trie. The classic introduction to bit-trie pattern that powers competitive programming and database query optimisers.
Complete Tries cheatsheet for FAANG interviews: core operations, 5 patterns, binary trie for XOR, decision guide, complexity table, and problem index covering all 20 trie problems.