Bit Manipulation and Low Level Optimization Questions

Covers understanding and applying bitwise operations and bit level techniques to solve algorithmic and systems problems. Topics include bit masking for isolating or setting fields, bit shifting for scaling and position manipulation, exclusive or tricks for swapping or parity, counting set bits, finding lowest or highest set bit, and using bitsets for compact state representation. Includes flag management and register style programming typical in embedded systems and hardware interfaces, as well as performance oriented techniques such as branchless programming and using processor population count instructions. Candidates should also be able to reason about when bit level approaches provide elegant or measurable improvements and when they become premature or harmful optimizations, and explain portability and endianness implications.