You've learned bitwise operations and common patterns.
Operators: AND, OR, XOR, NOT, shifts.
Common tricks:
- Check/set/clear/toggle bit .
- Count set bits (popcount).
- Clear or isolate lowest set bit.
- Check power of two.
XOR magic: Self-inverse property finds unique elements.
Bitmask DP: Represent sets as integers for compact state.
When to use:
- Subset enumeration.
- Compact state representation.
- Finding duplicates or missing elements.
- Low-level optimization.
Bit manipulation is a powerful tool. Learn it and you'll find clever solutions to problems that seem to require complex data structures.