Implementing algorithm

A well designed algorithm can be easily implemented, almost mechanically. However, there are many points to be considered in order to implement the algorithm in an efficient manner. These are:

Modularity

Breaking the tasks into different modules decreases coding and increases readability. For example if a program requires sorting at various points then a specific sorting procedure should be written for sorting the data. Care should be taken that the modularization does not make the program take more time to execute.

Example:

Let us consider a student's record which maintains student details, in sorted order, of the student's names. To add the name of a new student the name will be passed to sort module.

For example the existing student names are: Anand, Chitra, Nirmal.

If a new student Bharat is to be added in the list, this name will be passed to sort module. Let us see the steps of sort module algorithm.

Read the new student's name

Check the list till the name already in the list is greater than the new student's name or the list ends.

If a name is greater than the new student's name insert the new name before the name which is greater than the new name.

If list ends than add the name in the end of the list

In our example the loop terminates at the stage where Chitra is greater than Bharat and Bharat will be inserted before Chitra. If the new student's name is Manoj than the name will be added in the end list.

Procedure and Variable Names

Procedure and variable names should be self explanatory such as "Name", "Salary", "Total Amount" instead of single letters and meaningless words. This increases readability. Use variables of any length, but make sure the length of the variable is such that the computer's operating system supports and name variables and procedures accordingly. For example, DOS does not support more than eight characters.

Testing

Testing the program should be started with the smallest input value. Check the conditions which the program is supposed to handle. Verify the output for all possible invalid conditions.

Debugging

Implementing algorithm requires necessary tests to check whether the program is performing according to the requirement. The syntactical errors can be rectified during compilation. To eliminate logical errors one of the simplest method is writing a procedure that will print a set of statement at various points of execution. This can be removed after completing the implementation.