ALGORITHMList of instructions for carrying out some

process step by step.A sequence of instructions which has a clear

meaning and can performed with a finite amount of effort in a finite length of time.

Is a list of instructions for carrying out some process step by step.

History of AlgorithmThe word algorithm comes from the name of

the 9th century mathematician ABU ABDULLAH MUHAMMAD IBN MUSA ALKWARIZMI.

ALOGORISM – referred only to the rules of performing arithmetic using hindu-arabic numerals from the European Latin Translations of AL-Kwarizmi’s name into ALGORITHM by the 18th century.

EXPRESSIONS OF ALGORITHM1. Natural Languages

- rarely used for complex or technical algorithm.

2. Pseudocode and Flowchart- are structured way to express algorithm

3. Programming Languages- are primarily intended for expressing algorithms in a form that can be executed by a computer.

PROBLEM SOLVING CONCEPT

1. Identify the problem2. Understand the problem3. Identify alternative ways to solve the

problem4. Select the best solutions from the

alternatives5. List of instructions that enable you to

solve the problem by the selected method

6. Evaluate the solution

The problem steps:

Program Development Cycle

Problem Analysis

Program Design

Program Coding

Testing and Debugging

Documentation

Maintenance

FLOWCHARTIt is a diagram representing the logical

sequence in which a combination of steps or operations is to be performed.

It is consists of labeled geometrical symbols that are interconnected to provide pictorial representation of a data processing procedure.

A flowchart is actually a visual representation of an algorithm.

INPUT/OUTPUT SYMBOL(PARALLELOGRAM)

The input/output

symbol represents an

instruction to an input or an

output device.

PROCESSING SYMBOL(RECTANGLE)

This symbol is used to represent a group of program instructions

that performs a processing function of the program such as

to perform arithmetic operations, or to compare, sort

etc.

DECISION SYMBOL(DIAMOND)

This diamond-shape box denotes a

point in the program

where more than one path can be taken.

It is used to document points in the program where, based upon variable conditions, a branch to alternative paths is possible. The particular path that is chosen depends on the answer to a question or the result of a test which is inserted in the symbol.

PREPARATION SYMBOL(HEXAGON)

This symbol is used to represent an instruction or group of instructions

that will alter, or modify a program’s course of

execution. It is commonly used to specify operations

such as control, index registers, initialization,

setting, and in indicating switch loops.

TERMINAL SYMBOL(OVAL)

The terminal symbol is used to designate the beginning and the

end of a program, or a point of interruption. It can also be used elsewhere in the flowchart for

specifying error conditions , such as parity error checks or

detection of invalid characters.

PREDEFINED PROCESS SYMBOL(RECTANGLE WITH TWO VERTICAL BARS)

This symbol is a specialized process symbol that

represents a named operation or programmed step not explicitly detailed in the

program flow. As a subroutine, it can be used when a procedure needs to be

repeated several times. Rather than write the instructions for the procedure each time it is

needed, the predefined process symbol is used.

ON PAGE CONNECTOR(SMALL CIRCLE)

This is a non- processing

symbol which is used to connect

one part of a flowchart to

another without drawing flow

lines.

FLOW DIRECTION INDICATORS(ARROWHEADS)

Arrowheads are used to show the direction of processing or data flow. These are added to flow lines if a flowchart appears confusing in its layout.

OFF-PAGE CONNECTOR(SMALL PENTAGON)

This type of connector is used instead of the on-page

connector to designate entry to or exit from a page when a flowchart requires

more that one page.

FLOW LINES(VERTICAL/HORIZONTAL LINE)

Flow lines are used to show reading order or sequence in which flowchart symbols are to be read.