Write a function that takes a 32-bit binary representation of an unsigned integer $n$ and returns the count of its $1$ bits.

The binary representation of an unsigned integer is a sequence of $0$s and $1$s that represents the integer's value using base-2 notation. An example of the 32-bit binary representation of an unsigned integer $13$ is $00000000000000000000000000001101$.

Constraint:

• The input must be a 32-bit binary representation of an unsigned integer.

Note: The input is passed to the function as an unsigned integer variable. In this lesson, we have displayed it as a string of binary numbers solely for visualization purposes.

Let’s take a moment to make sure you’ve correctly understood the problem. The quiz below helps you check if you’re solving the correct problem: