We consider open addressing hashing, and implement it by using the Robin Hood strategy, that is, in case of collision, the element that has travelled the furthest can stay in the slot.
We hash elements into a table of size
, where each probe
is independent and uniformly distributed over the table, and
is a constant.
Let be the maximum search time for any of the elements in the
table. We show that with probability tending to one,
for some constants
depending upon
only.
This is an exponential improvement over the maximum search time in case of the standard FCFS (first come first served) collision strategy, and virtually matches the performance of multiple choice hash methods.