Bit Manipulation¶
| Problem | Complexity | Key Pattern |
|---|---|---|
| Counting Bits | O(n) |
DP on binary representation — "count set bits for 0..n", "Hamming |
| Reverse Bits | O(1) (fixed 32 iterations) |
Bit-level transformation — "reverse bits", "swap nibbles/bytes", |
| Single Number | O(n) |
XOR uniqueness — "find the element appearing once while others appear |