Data structure-and-algorithm hashing

1. Maryam Rani (124)

2. • A situation when the resultant hashes for
two or more data elements in the data
set, maps to the same location in the has
table, is called a hash Collision.
• In such a situation two or more data
element would qualify to be stored to the
same location in the hash table.

3. Two type of collision resolution:
• Open Hashing (Chaining)
• Closed Hashing (Open Addressing)

4. The difference between the two has to
do with:
 Whether collision are stored outside
the table (Open Hashing)
 Whether collision result in storing
one of the records at another slot in
the table (Closed Hashing)

6. Hash tables are commonly used to
implement many types of in memory
tables. They are used to implement
associative arrays(array whose indices
are arbitrary strings or other
complicated object).

7. Hash tables may also be used as dis-
based data structures and database
indices(such as in dbm).

8. Hash tables can be used to implement
caches i.e. auxiliary data tables that are
used to data, which is primarily stored
in slower media.

9. • Several dynamic languages, such as
Perl, python, javaScript, and Ruby use
hash table to implement objects.
• Hash Functions are used in various
algorithms to make their computing
faster.

10. • A symbol table in compilers- store and access
info about variable and functions each time
their name appears in program being compiled.
• In Game Programs: Avoid recomputing moves
by storing each board configuration
encountered with corresponding best move in a
hash table.