Kata

Complete the function power_of_two/powerOfTwo (or equivalent, depending on your language) that determines if a given non-negative integer is a power of two. From the corresponding Wikipedia entry:

a power of two is a number of the form 2ⁿ where n is an integer, i.e. the result of exponentiation with number two as the base and integer n as the exponent.

You may assume the input is always valid.

Examples

power_of_two?(1024) # true
power_of_two?(4096) # true
power_of_two?(333)  # false

power_of_two(1024) ==> True
power_of_two(4096) ==> True
power_of_two(333)  ==> False

PowerOfTwo.isPowerOfTwo(1024) // -> true
PowerOfTwo.isPowerOfTwo(4096) // -> true
PowerOfTwo.isPowerOfTwo(333)  // -> false

isPowerOfTwo(1024) // -> true
isPowerOfTwo(4096) // -> true
isPowerOfTwo(333)  // -> false

poweroftwo(1024) # true
poweroftwo(4096) # true
poweroftwo(333)  # false

isPowerOfTwo       1 `shouldBe` True
isPowerOfTwo       2 `shouldBe` True
isPowerOfTwo       6 `shouldBe` False
isPowerOfTwo       8 `shouldBe` True
isPowerOfTwo    1024 `shouldBe` True
isPowerOfTwo    1026 `shouldBe` False

powerOfTwo 1 `shouldEqual` true
powerOfTwo 2 `shouldEqual` true
powerOfTwo 6 `shouldEqual` false
powerOfTwo 8 `shouldEqual` true
powerOfTwo 1024 `shouldEqual` true
powerOfTwo 1026 `shouldEqual` false

power_of_two(0);     // returns false
power_of_two(16);    // returns true
power_of_two(100);   // returns false
power_of_two(1024);  // returns true
power_of_two(20000); // returns false

power_of_two(0); // false
power_of_two(1); // true
power_of_two(2); // true
power_of_two(37); // false
power_of_two(64); // true

Beware of certain edge cases - for example, 1 is a power of 2 since 2^0 = 1 and 0 is not a power of 2.