Full table quadratic searching for scatter storage

A. Colin Day

doi:10.1145/362705.362709

$.20 \ \ Programming Techniques R. MORRIS, Editor .15 Full Table Quadratic Searching for Scatter Storage A. COLIN DAY University College London, London, England The quadratic residue search method for hash tables avoids much of the clustering experienced with a linear search method. The simple quadratic search only accesses half the table. It has been shown that when the length of the table is a prime of the form 4n "k 3, where n is an integer, the whole table may be accessed by two quadratic searches plus a separate access for the original entry point. A search method is presented which is computationally simple, has all the advantages of the quadratic search, and yet accesses all the table in one sweep. KEY WORDS AND PHRASES: quadratic residue, searchmethod,hashtables, scatter storage, dictionary look-up, quadratic search,searching,hashing,hash code, clustering,collisions CR CATEGORIES: 3.7, 3.73, 3.74 Z tlJ .I Z o b-o~ \ h0 O5 CORRELATION FiG. 8. Stability of transformation. Distribution of the correlation coefficient on first (left curve) and second (right curve) application of the geometric projection. unknown. Such an application would be most welcome for further development of this approach. 0 1. Introduction$

Full table quadratic searching for scatter storage

Day, A. Colin

Follow Communications of the ACM , Volume 13 (8) Association for Computing Machinery – Aug 1, 1970