Bitmasking is a powerful technique used in algorithm design to represent sets and states using the binary representation of integers. Each bit in a number corresponds to whether an element is present or absent in a subset. This compact representation allows many subset and state-based problems to be solved efficiently, especially when the number of elements is small (typically ≤ 20).

In coding interviews, bitmasking often appears in problems involving subset enumeration, state compression, and optimization. Instead of storing sets explicitly, developers can use bit operations such as AND, OR, XOR, and bit shifts to manipulate states quickly. These operations are fundamental concepts from Bit Manipulation and are frequently combined with advanced techniques like Dynamic Programming for solving complex problems such as traveling salesman variations or assignment problems.

Common patterns you’ll encounter include:

• Enumerating all subsets using bit representations
• State compression in DP to reduce memory usage
• Tracking visited elements efficiently
• Optimizing brute-force search often paired with Backtracking or Enumeration

Practicing bitmask problems helps you develop a deeper understanding of binary operations and efficient state modeling—skills that are highly valued in technical interviews.