Sequential and Direct File Organization

This application has demonstration of the following algorithms

LISCH (Last Insertion Coalesced Hashing)
Progresive Overflow
Linear Quotient
Brent's Method

Application has static 10 byte data buffer and store this data in 20 byte allocated storage. Array size and Storage Size is Constant for Demonstration.

LISCH (Last Insertion Coalesced Hashing)

If collision present then algorithms search empty slot from end of list and decrease index for suitable location. First index calculated as follow

index =  key  % MOD_SIZE

Progressive Overflow

If collision present then algorithm increase the index one-by-oneand looks for next empty slot. First index calculated as follow

index =  key  % MOD_SIZE

Linear Quotient

If collision present then algorithm increase the position by and the following method

step_size = ( key / MOD_SIZE ) % MOD_SIZE

and looks for next empty slot. First index calculated as follow

index =  key  % MOD_SIZE

Brent's Method

If collision present then algorithm calculates the step_size as follow

step_size = ( key_1 / MOD_SIZE ) % MOD_SIZE

then if position in this step is not empty then algorithm calculates the cost of movement of this current collided item to another location and replace with current key. If movement has less step then we replace collision with current key and previous key moved to another location else we continue searching empty slot for current key.

Application Interface

1 - Click Generate Random Data Button 2 - Select LISCH, Progresive Overflow, Linear Quotient or Brent's Method 3 - Follow Logs

You can add data one by one from textbox

Limitations

MOD = 11 DATA STORAGE SIZE = 20

You can see how much step executed for each algorithm

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