Saturday, August 30, 2008

FLOWCHARTING AND ALGORITHMS - NAVARRA

In this week, we tackle about flowcharting and algorithms. I learned that flowcharting is a two – dimensional representation of an algorithm. I also learned that flowcharting is just a diagram representing the logical sequence in which a combination of steps is to be performed.

I also learned that algorithm is a finite set of instruction that specify a sequence of operations to be carried out in order to solve a specific problem.

I also learned that flowcharting uses a lot of symbols and procedures. The symbols that we discuss are:

· Terminal

– its shape is a rectangle whose corners are not pointed
– it is used to signify the beginning and the end.
· Preparation
– also called as the initialization
– it is used to represent instructions or groups of instructions that will alter a program’s course of execution.
– It is also used to select initial conditions.
· Input/Output
– its shape is like a rhombus.
– the data are to be read into the computer memory from an input device or the are to be passed from the memory to an output device.
· Processing
– performs any calculations that are to be done.
· Decisions
– signifies any decisions to be done.
– It only consist two decision, the true and the false
· On – page Connector
– its shape is circle.
– Shows the entry or exit point of the flowchart.
– A non – processing symbol used to connect one part of the flowchart to another without drawing flow lines.
· Off – page Connector
– its shape is an inverted pentagon.
– Designated entry to or exit from one page when a flowchart requires more than one page.
· Flow lines
– are lines with one arrow head.
– Signifies the process that is to be executed next.

We also discuss about the three basic control structures. And that are the sequence, selection and repetition.

Sequence
– a process executed from one to another in a straightforward manner.

Selection
– uses the term if, then and else.
– There is a choice that being provided between alternatives.
– The flowchart already has a two direction, the true and the false which is dependent to the choice of the person doing it.

Repetition
– provides a repetitive execution of an operation or routine while the condition is true.
– The condition is evaluated before executing any process statement.

And lastly, we discuss about the arithmetic symbols that are used and they are the:

Addition +
Subtraction -
Multiplication *
Division /

Other symbols are:

= - equal
< > - greater or lesser that
≥ ≤ - greater than or equal to
- lesser than or equal to
║ - or
&& - and
! - not

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