Power of Two | Problems

You're given an integer n. Determine whether n is a power of two — that is, whether some non-negative integer k satisfies n = 2^k. Return true or false accordingly.

The powers of two start 1, 2, 4, 8, .... Neither zero nor any negative number qualifies here.

Input Format

Implement isPowerOfTwo(n). Inputs below show JavaScript function arguments; there is no stdin parsing.

Output Format

Return the result described in the statement.

Sample Input and Output

Example 1 · Run Sample

Input

n = 1

Output

true

Example 2

Input

n = 16

Output

true

Example 3

Input

n = 3

Output

false

Constraints

-2^31 <= n <= 2^31 - 1

Test Cases (3)

Case 1

Args: [1] Expected: true

Case 2

Args: [16] Expected: true

Case 3

Args: [3] Expected: false

Topics

Matrix BFS DFS

Bit Manipulation

javascript

1
2
3

function isPowerOfTwo(n) {
  return n > 0 && (n & (n - 1)) === 0;
}

Time: O(1) | Space: O(1)

Saved in this browser only. Private to you.