Hashing

Hashing

1. Definitions

   • Hash table
     • The table gets it name from the method used to determine the row to use. The hash value generated by applying the hash function to the key is the table index where the record should be stored if the row is free
   • Hash Function
     • Is a function H, applied to a key k, which generates a hash value H(k) of range smaller than the domain of values k
   • Hash value
     • Hash value
       • Is the value generated by the application of the hash function to the key. This value can be used as the hash table index where the key and any associated data can be stored if this table location is free
   • Hash Key
     • Is the key that the function is applied to
   • Hashing
     • The process of applying a hash function to a key to generate a hash value

2. Hash tables

   • Inserting into Hash tables
     • If there is a hash table with the 99 entries and the user wants to insert a input into the table and takes the last 2 digits then the program takes the last two digits and places them into the corresponding table entry
       • Collisions
         • If there are two inputs that have the same two digits for example
   • Searching Hash Tables