Solution: The Number of Good Subsets

Statement

For a given integer array, nums, you can say that a subset of nums is called “good” if the product of its elements can be expressed as a product of one or more distinct prime numbers, i.e., no prime factor appears more than once.

For example, if nums $= [1, 2, 5, 6]$, then:

• $[2, 5]$, $[1, 2, 5]$, and $[6]$ are good subsets with products $2 \times 5 = 10$, $1 \times 2 \times 5 = 10$, and $2 \times 3 = 6$, respectively.

• $[2, 6]$ ...