1. (4 points) Suppose we have a hash table of size 29 and we want to implement a system for looking up a friend's information given his/her name. Which of the following hash functions is the best? Justify your choice. (Assuming none of the names is empty.) (a) h(x) = x (b) h(x) = n % 13, where n is the number of characters in x (c) h(x) = (ord(x[0])+ ord(x[-1])) % 29, where x[0] is the first character in the name and x[-1] is the last. (d) h(x) = 29 (e) h(x) = 11 Σ ord(x[i]), where n is the number of characters in x, x[i] the ith character in x, i=0 and ord(c) returns the ordinal value of a character. (Instruction on the Σ summation symbol https://www.mathsisfun.com/algebra/sigma-notation.html.)

1. (4 points) Suppose we have a hash table of size 29 and we want to implement a system for looking up a friend's information given his/her name. Which of the following hash functions is the best? Justify your choice. (Assuming none of the names is empty.) (a) h(x) = x (b) h(x) = n % 13, where n is the number of characters in x (c) h(x) = (ord(x[0])+ ord(x[-1])) % 29, where x[0] is the first character in the name and x[-1] is the last. (d) h(x) = 29 (e) h(x) = 11 Σ ord(x[i]), where n is the number of characters in x, x[i] the ith character in x, i=0 and ord(c) returns the ordinal value of a character. (Instruction on the Σ summation symbol https://www.mathsisfun.com/algebra/sigma-notation.html.)

Database System Concepts

7th Edition

ISBN:9780078022159

Author:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Publisher:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Chapter1: Introduction

Section: Chapter Questions

Problem 1PE

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