30秒学会 C# 片段 – IsPowerOfTwo

Returns true if the given number is a power of 2, false otherwise.

Use the bitwise binary AND operator (&) to determine if n is a power of 2.
Additionally, check that n is different from 0.

代码实现

public static partial class _30s 
{
  public static bool IsPowerOfTwo(ulong n) 
  {
    return (n != 0) && ((n & (n - 1)) == 0);
  }
}

使用样例

_30s.IsPowerOfTwo(0); // false
_30s.IsPowerOfTwo(1); // true
_30s.IsPowerOfTwo(8); // true