Solution: Continuous Subarray Sum

Statement

Given an integer array nums and an integer k, determine if nums contains a good subarray. Return true if such a subarray exists; otherwise, return false.

A subarray of nums is considered good if:

• Its length is at least $2$.

• The sum of its elements is a multiple of k.

Notes:

• A subarray is defined as a contiguous sequence of elements within an array.

• An integer x is a multiple of k if there exists an integer n such that x = n * k. Note that 0 is always considered a multiple of k.

Constraints:

• $1 \leq$ nums.length $\leq 10^4$

• ...