Bitwise AND - Counting Set Bits (Hamming Weight) — Bit Manipulation Patterns
The Bitwise AND - Counting Set Bits (Hamming Weight) pattern applies when you need the Bitwise AND - Counting Set Bits (Hamming Weight) technique within the Bit Manipulation Patterns pattern. Its time complexity is O(1) and space complexity O(1). It is used in 2 problems on Thita, including Number of 1 Bits and Power of Two. Common variations are Bitwise Operations - Power of Two/Four Check and Bitwise XOR - Finding Single/Missing Number.
Count number of 1 bits (Hamming weight) using bitwise AND operations.
Bitwise AND - Counting Set Bits (Hamming Weight) is one of the 4 subpatterns of the Bit Manipulation Patterns pattern, which covers xOR tricks, counting bits, power-of-two checks, and Hamming weight. The whole pattern is about 1.5 hours of study. This subpattern is a depth topic for once the core techniques are automatic.
What Bitwise AND - Counting Set Bits (Hamming Weight) covers
Master bit manipulation including XOR tricks, counting bits, power of two checks, and bit masking. Essential for optimization and low-level problems. Problems in this subpattern are usually searched for as Hamming weight, count set bits, number of 1 bits, popcount, leetcode 191.
How to practise Bitwise AND - Counting Set Bits (Hamming Weight) on Thita.ai
Read the theory for Bitwise AND - Counting Set Bits (Hamming Weight), then work the problems attached to it in the browser editor. Your solution runs against the problem's test cases, and the AI coach offers a hint about the technique you are missing rather than a finished solution. Progress is tracked per subpattern, so the Bit Manipulation Patterns tracker shows this one as covered once you have solved its problems.
Other subpatterns in Bit Manipulation Patterns
- Bitwise Operations - Power of Two/Four Check — Check if number is power of two or four using bitwise operations.
- Bitwise XOR - Finding Single/Missing Number — Use XOR properties to find single number, missing number, and duplicates.
- Bitwise DP - Counting Bits Optimization — Count bits for range of numbers using DP with bit manipulation optimization.
Related DSA patterns
- Dynamic Programming (DP) Patterns — Fibonacci, Kadane, knapsack, LCS, LIS, edit distance, grid paths, and word break.
- Graph Traversal Patterns (DFS & BFS) — DFS/BFS traversal, topological sort, shortest paths, Union-Find, and MST.
- Design Patterns — Tries, LRU/LFU cache, and data structure design.
- Segment Tree & Fenwick Tree Patterns — Range queries, point updates, and inversion counting.
Where to go next
Bitwise AND - Counting Set Bits (Hamming Weight) is one lesson in a 16-pattern DSA course. If you are preparing end to end, work the interview-critical patterns first and use the pattern sheet as the checklist; if you are here for one technique, the Bit Manipulation Patterns guide is the shortest path back to the rest of it.