Coding · Easy · Free
Check if a number is a power of two
CodingBit ManipulationFresher
Approach
- A power of two has exactly one set bit.
- Use
n > 0 && (n & (n-1)) == 0.
Java Solution
Java
boolean isPowerOfTwo(int n) {
return n > 0 && (n & (n - 1)) == 0;
}| Complexity | |
|---|---|
| Time | O(1) |
| Space | O(1) |
Interview tip: Explain why
n & (n-1) clears the lowest set bit.