Using that definition, write a function to meet the following specification. Your answer may be written recursively or non-recursively. The return value for the empty tree is zero. Linear probing can lead to primary clustering. In one or two sentences, describe what is meant by primary clustering.
Primary clustering is the tendency of items to group together in the hash table.
Over time, these groups, or clusters, merge together to form larger clusters, and this leads to an increase in collisions.