Divide and Conquer

1
Divide and Conquer Methodology
2
Solve a Complex Problem

• Identify a number of simpler problems within
  the original problem

3
Modular Programming

• The modular programming methodology goes a step
  further in specifying how the simpler problems sho
  uld be designed.
• Desirable properties
• Each simpler problem can be solved, programmed an
  d 
• tested independently from each other.

4
Divide and Conquer

• Break a complex problem into
• a number of simpler and independent problems
• we can manage the complexity easier

5
Example

• Design Algorithm
• Design Classes

6
Information Hiding (1)
7
Information Hiding (2)

• Direct access
• The variables have public access and they
  are directly 
• accessible ( exposed) to the user.
• Indirect access
• The variables have private access and
  they indirectly 
• accessible ( hidden) to the user
  through public methods

8
Information Hiding (3)
9
Information Hiding (4)

• There are 2 aspects in the process of providing
  information
• Implementation  How is the data stored that are
  used to provide the information.
• Functionality  What operations are allowed on
  the information.
• Indirect access technique, makes the 
• functionality and implementation  decoupled

10
Information Hiding (5)