Bit Manipulation - Counting/Shifting

The Bit Manipulation - Counting/Shifting technique is applied when tackling problems characterized by specific invariants in the problem state or constraints:

• Core Strategy: Count, shift, or accumulate individual bits to compute a numeric property (popcount, reversal, running totals).
• When to use: Look for opportunities where repeated re-computation can be replaced by maintaining monotonic properties, state windows, or relational pointers.
• Interview Signal: Demonstrating this pattern shows mastery of Bit Manipulation foundations, reducing worst-case algorithmic complexity.