Given an integer array nums and an integer k, return true if nums has a continuous subarray of size at least two whose elements sum up to a multiple of k, or false otherwise. An integer x is a multiple of k if there exists an integer n such that x = n * k. 0 is always a multiple of k. Example 1: Input: nums = [23,2,4,6,7], k = 6 Output: true Explanation: [2, 4] is a continuous subarray of size 2 whose elements sum up to 6. Example 2: Input: nums = [23,2,6,4,7], k = 6 Output: true Explanation: [23, 2, 6, 4, 7] is an continuous subarray of size 5 whose elements sum up to 42. 42 is a multiple of 6 because 42 = 7 * 6 and 7 is an integer. Example 3: Input: nums = [23,2,6,4,7], k = 13 Output: false Constraints: 1 <= nums.length <= 105 0 <= nums[i] <= 109 0 <= sum(nums[i]) <= 231 - 1 1 <= k <= 231 - 1