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Problem Solving using Computer

Steps

1. Understanding of the problem ?2. Methods and Logic to solve the problem.

3. Flow-Chart /Algorithm / Decision Tables /

Pseudo Code.4. Computer language ? Coding ? (Programming)

5. Execution and producing the results.

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Steps1. Understanding of the problem :- Problem

should be clear to us. We should know, whatis given ? What is to be done ?

2. Methods and Logic to solve the problem :We should know how to solve the problem.

If we dont know the method and logic tosolve the problem, the computer cant help.

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The computer can do only five operations :

Additions

Substractions

Multiplications

Divisions

Compare

The computer can do these calculation at very high

speed.

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4.Computer Language : Why we need computerlanguage ? Because, computer understands

only the computer language, the computer

dont understand our languages like English,Hindi, Punjabi etc.

So we have to give instructions in one of the

computer languages ?

Program Instructions written in computer

language.

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Types of Computer Languages :-

A. Low level languages

B. High level languages

C. Data Base languages

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A)Low-level languages Historically Low-level languages weredeveloped first. Low level languages are machine dependent.Every manufactures develop their own language. The low-level languages vary from machine to machine. If one learnsand works on one machine, after changing the computer, one

has to learn again new language for the new machine. That iswhy the computer remains with the manufactures or with theuniversities and with the research institutes. Low levellanguages are of two types

a) Machine languages

b) Assembly languages

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a) Machine language : Strings of numbers givingspecific instructions.

Example :

+ 1300042774

+ 1450212674

+ 1303245574

These codes vary from machine to machine. Learning ofthe machine language is difficult.

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b) Assembly Language : (Symbolic

Language) Instead of numeric code,

some symbols are used.

Examples :

LOAD BASEPAY

ADD OVERPAYSTORE GROSSPAY

Symbols also vary from machine to machine.

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B) High Level Languages : High Level languages are

machine independent. These are more near to ourproblems. Easy to learn and with less time. We can

learn anyone high level language and that will

work on any computer of any company in any part

of the world.

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The various High Level Languages are :-

BASIC Beginners All Purpose SymbolicInstruction Code

FORTRAN Formula Translation

COBOL Common Business Oriented Language PASCAL Named after Blais Pascal

C The latest and most powerful language.

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TRANSLATORS

Actual Processing is done in only in machine

languages. All Assembly language and High levellanguage programs have to be translated into the

machine language of that particular machine.

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Translators are provided by the manufacturers.

There are three types of translators

i) Assembler

ii) Interpreter

iii) Compiler

Translator first finds the grammatical mistakes and if

there is no grammatical mistake then translate it intothe machine language.

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i) Assembler : Assembler translates only the assemblylanguage program into the machine language.

ii) Interpreter : Check and translate the high levellanguage programs into the machine language line byline.

Interpreter is available only for BASIC language

iii) Compiler : Reads the whole high level program, ifthere is no grammatical error, then it translates thewhole program into the machine language.

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Source Code : Program written in High-

level languages.

Object Code : Translated program in

machine language fromhigh level languages.

There are two types of Errors

i) Syntax Errorsii) Logic Errors

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Syntax Errors : Every computer language has

its own grammer and the rules of the language.

If the program is not according to the rules of

the language, those errors are called Syntax

errors (Grammatical Errors). Syntax Errors are

easy to detect and easy to remove.

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Logic Errors If there is no Syntax error, still

program may or may not work. If our method or

logic is wrong, the program wont work

(GIGO).

eg. - Diversion by zero.

- Square root of negative

numbers.

- Number out of range, etc.

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5.Execution and Results :-

Object Program + Data ResultsActual processing is done with the object program.

Any change or correction in the problem, has to be

made first in the source program, then source

program is translated into the object program. No

direct change in the object program.

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If some logic error is there, you may not get the

result. You have to first correct logic and thenmake the necessary correction in the source

program and then translated into the object

program and finally execution.

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C) Data Base Languages :

DBASE-III, IV FOXPRO

ORACLE

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Data Base Languages are :

- Easy to use- Much simpler

- Popular among non-professional

- Learning with less time- Language as well as package

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Language Database languages have all the features ofhigh-level languages.

Package Database languages have some command to dosome jobs. Commands can be used directly and there is noneed of any programming.

Other packages are :

- MS-WORD

- MS-EXCEL

- MS-ACCESS

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Example Data Base of Students :

Data Base Structure :

Field Name TypeW

idth

NAME Character 20

D-O-B Date 8

Address Character 30

City Character 15

PIN Numeric 6

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Example of Data Base : Student

NAME D-O-B ADDR ESS CITY PIN

1. RAM 15/10/93 145/Sec. 15 Chandigarh 160015

2. SHAM 10/05/92 165/Sec.- 19 Chandigarh 160019

3. SITA 10/06/93 989/Sec.- 45 Chandigarh 160045

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Facilities available in Database Languages

1. Creation of Data Base and Data-Base Structure

2. Entering the Data Records

3. Editing the Data Records

4. Adding New Records5. Deleting Records

6. Retrieving and Searching the records

7. Displaying the records

8. Preparing the reports

9. Quarries

10. Sorting etc.

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