When to Use Bit Manipulation

Look for these signals that bit manipulation might help:

$1.$ The problem mentions binary, bits, or powers of 2.

$2.$ You need to represent subsets of a small set ($n \leq 20$).

$3.$ You need to toggle, check, or modify individual flags or states.

$4.$ The problem asks for $O(1)$ space and involves finding unique elements or duplicates.

$5.$ You need constant-time operations on small sets (bitmask DP).

If you see any of these patterns, consider whether bitwise operators could simplify your solution.