How can i use Hellinger Distance on array of different length?

I have to use Hellinger distance to compare arrays that are not the same length.

How do you do this correctly? Putting a zero in the missing fields for the shorter array does not sound like the best method to me.

Some more info on my data:

Most array dimensions are (1,58), but a some others are (1,28). Arrays contain numbers from 1 to 3.

Example:

Array1=[1 1 3 2 3]

Array2=[2 3 1 1]

One possible solution: newArray2=[2 3 1 1 0]

Is possible to use Hellinger Distance in this case? Is there any other distance function that could solve my problem?

I'm using Helliger in K-means because it's what the author of a paper I'm reading used. So, I would like to solve this issue using Hellinger.

Thanks.