Search⌘ K
AI Features

Solution: The Number of Good Subsets

Explore how to use dynamic programming combined with bit masks to count subsets whose product has unique prime factors. This lesson teaches you to efficiently track prime factor usage and combine subsets while ensuring no repeated primes. Understand the algorithm to solve the problem in linear time with fixed space.

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]= [1, 2, 5, 6], then:

  • [2,5][2, 5], [1,2,5][1, 2, 5], and [6][6] are good subsets with products 2×5=102 \times 5 = 10, 1×2×5=101 \times 2 \times 5 = 10, and 2×3=62 \times 3 = 6, respectively.

  • [2,6][2, 6] ...