A Common-Sense Guide to Data Structures and Algorithms

Hashing with Hash Functions

Do you remember those secret codes you used as a kid to create and decipher messages?

For example, here’s a simple way to map letters to numbers:

A = 1

B = 2

C = 3

D = 4

E = 5

and so on.

According to this code,

ACE converts to 135,

CAB converts to 312,

DAB converts to 412,

and

BAD converts to 214.

This process of taking characters and converting them to numbers is known as hashing. And the code that is used to convert those letters into particular numbers is called a hash function.

There are many other hash functions besides this one. Another example of a hash function is to take each letter’s corresponding number and return the sum of all the numbers. If we did that, BAD would become the number 7 following a two-step ...