21.2 Common hash functions

Will the hash function and expected key likely work well for the following scenarios? Hash function: key % 40 Key: 4-digit even numbers Hash table size: 40

No

For a decimal mid-square hash function, what is the bucket index for key = 110, N = 200, and R = 3?

10

For R = 3, what are the middle bits for a key of 9? 9 * 9 = 81; 81 in binary is 1010001.

100

For a 1000-entry hash table, compute the multiplicative hash for the following strings using the specific initial value and hash multiplier. Initial value = 0 Hash multiplier = 1 String = BAT

215

For a 1000-entry hash table, compute the multiplicative hash for the following strings using the specific initial value and hash multiplier. Initial value = 0 Hash multiplier = 1 String = TAB

215

For a decimal mid-square hash function, what is the bucket index for key = 112, N = 1000, and R = 3?

254

For a 1000-entry hash table, compute the multiplicative hash for the following strings using the specific initial value and hash multiplier. Initial value = 17 Hash multiplier = 3 String = WE

483

For a decimal mid-square hash function, what are the middle digits for key = 40, N = 100, and R = 2?

60

For a binary mid-square hash function, how many bits are needed for an 80 entry hash table?

7

Will the hash function and expected key likely work well for the following scenarios? Hash function: key % 1000 Key: 6-digit employee ID Hash table size: 20000

No

Will the hash function and expected key likely work well for the following scenarios? Hash function: key % 1000 Key: Customer's 3-digit U.S. phone number area code, of which about 300 exist. Hash table size: 1000

No

Will the hash function and expected key likely work well for the following scenarios? Hash function: key % 1000 Key: Selling price of a house. Hash table size: 1000

No

Will the hash function and expected key likely work well for the following scenarios? Hash function: key % 250 Key: 5-digit customer ID Hash table size: 250

Yes