Given a list of non-negative numbers and a target integer k, write a function to check if the array has a continuous subarray of size at least 2 that sums up to the multiple of k, that is, sums up to n*k where n is also an integer.
Input: [23, 2, 4, 6, 7], k=6
Explanation: Because [2, 4] is a continuous subarray of size 2 and sums up to 6.
Input: [23, 2, 6, 4, 7], k=6
Explanation: Because [23, 2, 6, 4, 7] is an continuous subarray of size 5 and sums up to 42.
The length of the array won't exceed 10,000.
You may assume the sum of all the numbers is in the range of a signed 32-bit integer.