14. Definition and Properties of Algorithm
In Webster's dictionary, the word "Algorithm" is defined as "any special
method of solving a certain kind of problem". But in computer science it
has a special meaning. It means a step by step procedure for solving a
problem by a computer. An algorithm has following properties.
1. An algorithm must be composed of a finite number of steps. Each
step may be another algorithm composed of several steps.
2. Each step of the algorithm must be definite. The meaning of the
operation must be clear. We cannot have an operation like "add 2 or
3 to x" in an algorithm.
3. The steps must be effective; each step can at least in principle be
done by a person using pencil and paper in finite amount of time.
Performing arithmetic on integers is an example of an effective
operation, but arithmetic with real numbers is not necessarily
effective, since some values may be expressible only by an infinitely
long decimal expression
4. The algorithm may have one or more inputs but it must have at least
one output.
5. An algorithm must terminate after a finite number of operations.
There is another word for an algorithm which obeys all of the above
properties except termination, and that is computational procedure.
An operating system of a digital computer is an example of a
computational procedure since it does not terminate, but continues in
Showing posts with label Language. Show all posts
Showing posts with label Language. Show all posts
Developing the system
8. Developing the system
Demand increases day by day. So new systems should be introduced.
This is done by introducing new programs and new versions of
programs. Sometimes new machines come up with extra facilities.
Existing systems may not support these facilities. At that time developed
programs are necessary for better utilisation of machines.
9.Scientific research
Scientific research requires computers for implementing the theory into
practice. Huge numbers of calculations are required for this purpose.
Only a computer program can help the scientists out. There are some
programs which are useful for scientific calculations. For example,
FORTRAN, C++, Mathematica, Math Lab. Simulation is also very
necessary for research, which can be performed using simulation
packages.
Purpose of Programming
5. Fourth Generation Languages
Scientists are trying to develop computer languages like human
languages. They have not been successful but may be successful in near
future. These languages have greater built-in facility such as database
query, searching, sorting and interfacing. FoxPro, Cobol, Visual Basic,
MS Access, Oracle Forms and Reports, SQL systems make use of such
programs or languages. These are also known as the Fourth Generation
Languages (4GL).
6. Purpose of Programming
There are several purposes of programming. These are discussed below.
7. Computer program for automated systems
Different offices need different system. So a ready made software is not
enough for this purpose. Special programs should be written for office
automation. These softwares may be used for accounting, payroll
systems, machine control, industrial control, billing system of electricity,
telephone and water, result processing of examination etc. It is important
to develop these softwares properly because the output of the whole
system depends on the output of the computer system.
C++, Mathematica, Math
Lab. etc..
Visual Basic, SQL, ORACLE.
Result Processing.
Principles of Programming
3. Different Types of Language
Low level languages
In old days computers were very large and were not much reliable.
Programming was done by switches and there was no facility to use the
program. This approach of computer programming was completely a
hardware technology. Next the approach of machine language comes up.
In this approach instruction set of the computer consists of some
numerical digits. This instruction set is used to build up a program. This
code is difficult to understand for human beings. Next assembly
language was introduced. In assembly language the numerical codes are
replaced by suitable names which are understandable. This has made
programming easier.
4. High level languages
This type of languages are like English language. But this is more
structured. Actually this type of languages support mathematical
notations used in arithmetic expressions. There are some special rules for
writing programs in high level languages. Pascal, C, C++, Mathematica,
Java, Math lab etc. Ada are all high level languages. High level
languages are easy to write, compile and suitable for error correction.
COMPUTER PROGRAMMING
Definition of Programming
Programming is writing instructions for a machine specially a computer.
The machine which works differently according to the instructions given
to it is called a programmable machine. The jobs of these machines are
not fixed. We can change the working plan of the machine by changing
the instructions or programs. Computers are machines that can
understand the instruction and work properly according to the
instructions given.
In short, programming means step by step instructions for solving a
problem by computer.
What is a Language?
The instruction given to the computer must have a particular format.
Computers are unable to understand human language. There are several
levels of format or language which a computer can understand. The
interest of understanding computer languages increases day by day.
History of computer languages is as old as computer science. This is
described in the following sections.
Programming is writing instructions for a machine specially a computer.
The machine which works differently according to the instructions given
to it is called a programmable machine. The jobs of these machines are
not fixed. We can change the working plan of the machine by changing
the instructions or programs. Computers are machines that can
understand the instruction and work properly according to the
instructions given.
In short, programming means step by step instructions for solving a
problem by computer.
What is a Language?
The instruction given to the computer must have a particular format.
Computers are unable to understand human language. There are several
levels of format or language which a computer can understand. The
interest of understanding computer languages increases day by day.
History of computer languages is as old as computer science. This is
described in the following sections.
