Question 1

How do you check if a number is a power of two?

Accepted Answer

A number is a power of two if it has only one bit set. You can check this with the expression (n > 0) && ((n & (n - 1)) == 0).

Question 2

How do you count the number of set bits in an integer?

Accepted Answer

There are several ways to do this, including Brian Kernighan's algorithm, which repeatedly flips the least significant set bit until the number becomes zero. Many modern processors also have a built-in instruction for this (e.g., POPCNT).

Bit Manipulation Interview Questions

Related Algorithm Guides