ALGORITHM List 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 Algorithm The 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 ALGORITHM Natural Languages - rarely used for complex or technical algorithm. Pseudocode and Flowchart - are structured way to express algorithm Programming Languages - are primarily intended for expressing algorithms in a form that can be executed by a computer.

PROBLEM SOLVING CONCEPT

The problem steps: Identify the problem Understand the problem Identify alternative ways to solve the problem Select the best solutions from the alternatives List of instructions that enable you to solve the problem by the selected method Evaluate the solution

Program Development Cycle Problem Analysis Program Design Program Coding Testing and Debugging Maintenance Documentation

FLOWCHARTING SYMBOLS

FLOWCHART It 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) 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. This diamond-shape box denotes a point in the program where more than one path can be taken.

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.