1. KIM, MCA Programme, kalol
Sub: : Fundamental of Programming(FOP)
Chap: 1 : Introduction to Programming: Algorithms and Flowcharts
Presented By
Tejas Modi
Asst. Professor,
KIM, MCA Programme, kalol
TEJAS MODI

2. Chap: 1 : Introduction To Programming
Program and Programming
Programming Language
Compiler, Interpreter
The Process of Compilation
Linker, Relocation, Loader
Generation of Languages
Classification of Programming Languages
Algorithms
Flowcharts
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3. Program and Programming
A program is set of logically related instruction that arranged in a sequence and guides the computer in solving a problem.
Programming
The process of writing a program is called programming.
There are two ways in which one can acquire a program.
Packaged Software
Customized Software
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4. Computer Software Computer Software can classified into two categories
System Software: it is a collection of programs that interface with the hardware.
Application Software: it is written to enable the computer to solve a specific data processing task.
Computer Software
System Software
Application Software
Language Translator
Operating System
Utilities
Special purpose Program (Loader, Linker)
Pre – Written Software
User – Written Application
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5. Programming Language System Programming Languages
A programming language is composed of a set of instruction in a language understandable to the programmer and recognizable by a computer.
System Programming Languages
O.S.
Application Programming Languages
Business and Scientific application, Payroll, inventory etc.
Low-level Languages:
Machine Language (Machine Code)
Assembly language (Mnemonic Code)
High-level Language
Basic C
COBOL (Common Business Oriented Programming Language)
FORTRAN (Formula Translation Language)
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6. Compiler, Interpreter, Loader, Linker
A high level program source code transfer into a form of machine under standable code, this process is done by compiler.
It is Software.
Diagnostics
The process of translating, the compiler the source program statement wise and check for errors. In case of any error, the computer generates a printout of same, this action is known as diagnostic.
Interpreter is another type of translation software.
Source Program in High Level
Compiler
Object Code in Machine Language
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7. Difference between Compiler Interpreter
Scans the entire program before translating it into machine code.
Convert the entire program to machine code and only when all the syntax errors are removed does execution take place.
Slow in debugging, i.e. removal of mistakes from a program.
Execution time is less.
Interpreter
Translates and executes the program line by line.
Each time the program is executed, every line is checked for syntax error and the converted to the equivalent machine code.
Good for fast debugging.
Execution time is more.
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8. Compiling and Executing High level Language program
It consists two step
Analysis of the source program.
Synthesis (creation) of the object program in the machine language of specific machine.
A Source language is described using lexical rules, syntax rules and semantic rules.
Lexical rules specify the valid syntactic element or word of language. (identifier, operator delimiter etc.)
Syntax rules specify the way in which valid syntactic elements are combined to form the statements of language.
Syntax rules are often described using a notation known BNF (Backus Naur Form) grammar.
Semantic rules assign meanings to valid statements of language.
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9. The Process of Compilation
Source
Program
Lexical
Analysis
Syntactic
Semantic
Symbol
Table
Other
Tables
Code
Generator
Linker and
Loader
Lexical Rules
Syntax Rules
Semantic Rules
Intermediate
code
Object Code
Executable Code
Object Code from
Other Compilations
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10. Linker & Loader Linker Loader Linking Loader and Linkage Editor
Linking resolves symbolic references between object program.
Linking of the translated program with other object programs needed for execution.
Loader
Loader means physically placing the machine instruction and data into main memory.
A loader is a system program that accepts object programs and prepares them for execution and initiates the execution.
The function of the loader are as follows:
Assignment of load-time storage area to the program.
Loading of program into assigned area.
Relocation of program to executed properly from its load time storage area.
Linking of programs with one another.
A loader is program that places a program’s instruction and data into primary storage (RAM) locations.
Linking Loader and Linkage Editor
The machine language program produced by the translator must normally be combined with other machine language program residing within the library to form a useful execution unit.
This process of program combination is called linking and the software that performs this operation is variously known as linking loader or a linkage editor.
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11. Generation of Languages
The 1GL are low – level languages that are machine language.
The 2GL are also low-level languages that generally consist of assembly languages.
The 3GL are high – level such as C.
The 4GL are languages that consist of statements similar to statements in a human language. Fourth generation languages are commonly used in database programming.
The 5GL are programming language which is based around solving problems using constrains given to the program, rather than using an algorithm written by a programmer. Most constraint-based and logic programming languages and some declarative languages are fifth-generation languages. A good example of a fifth generation language is artificial intelligence research. Prolog, OPS5(Official Production System), and Mercury are examples of fifth-generation languages.
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12. Classification of Programming Languages
High – level Languages
Low – level Languages
Algorithmic
(COBOL, FORTAN, C )
Procedural
Non - Procedural
Problem Oriented
Object Oriented
( C++, Java )
Scripting
( VB, PERL )
Functional
( LISP, ML )
Logic Based
( PROLOG )
Numerical
( MATLAB )
Symbolic
( MATHEMATICA )
Publishing
( LATEX )
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13. Structure Programming
Structure programming can be defined as a
Top – down analysis:
Subdivision of a problem (First we solve smaller problem)
Hierarchy of tasks
Modular Programming:
It is a program that is divided into logically independent smaller section.
Structure Code:
It is a method of coding, i.e. writing a program that produce a well organized module. (Never use GOTO).
A high level language support some structured control statement.
The process of Programming:
Understand the problem to be solved
Think & design the solution logic
Write the program in chosen programming language
Translate the program into machine code
Test the program with sample data
Put the program into operation
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14. Algorithms Example of an algorithm, for making a pot of tea
An algorithm is a part of the plan for computer program, an algorithm is ‘an effective procedure for solving a problem in a finite number of step’.
Example of an algorithm, for making a pot of tea
Key feature of an algorithm
Sequence (also known as process): each step or process in the algorithm is executed in the specified order.
Decision (also known as selection): outcome of the decision is based on some condition.
Repetition (also known as iteration or looping)
Variables
A variable is a data name that may be used to store data value.
Variables and data types
Numerical
Alphabetic
Logical data
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15. Algorithms Different ways of Starting Algorithms Step-form:
Step-form is in written form, the written form is just normal language.
Ex: Construct a algorithm for interchange the numeric value of two variable
1. START A=B
2. PRINT “ENTER THE VALUE OF A & B” 6. B=C
3. INPUT A, B PRINT A, B
4. C=A END
Pseudo-Code
Pseudo-code is also in human language but tends toward more precision by using a limited vocabulary. It is similar to 3GL.
There is no standard for pseudo-code, it is generally quite easy to read and use.
Ex: dowhile kettle_empty
Add_water_to _kettle
end dowhile
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16. 3. Flowcharts
A flowchart provides appropriate step to be followed in order to arrive at solution to a problem.
It is a program design tool which is used before writing the actual program.
Flowchart are generally developed in the early stages of formulating computer solution.
Standards for Flowcharts
Flowcharts must be drawn on white, unlined 81/2” x 11” paper, on one side only.
Flowcharts start on the top of the page and flow down and to right.
Only standard flowcharting symbols should be used.
A template to draw the final version of flowchart should be used.
The contents of each symbols should be printed readable.
English should be used in flowchart, not programming language.
The flowchart for each subroutine, if any must appear on a separate page. Each subroutine begins with a terminals symbols with the subroutine name and a terminal symbols labeled return at the end.
Draw arrow between symbols with a straight edge and use arrowheads to indicate the direction of the logic flow.
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17. Flowcharts Symbols Start or end of the program of flowchart Flow lines
Add Comments or furnish clarifications
Computational steps or processing Function of a program
Input entry or Output display operation
Decision making and branching operation
Connects remote parts of flowchart on the same page
A magnetic Tape
A magnetic Disk
Connects remote portion of the flowchart not on the same page
Flow lines
Start or end of the program of flowchart
Display
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18. Flowcharts Guidelines for flowcharting:
There should be logical Start and Stop.
Flow is from left to right or top to bottom.
Only one flow line should emerge from a process symbol.
Only one flow line should enter a decision symbol.
Only one flow line is used in conjunction with a terminal symbol.
If the flowchart becomes complex, connector symbols should ne used
In decision symbol only one input indicated by one incoming flow line and one output flowing out. The decision and process symbol are connected by flow lines.
Iteration or looping is depicted by a combination of process and decision symbols placed in proper order.
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19. INPUT SALARY OF AN EMPLOYEE
Ex: Give 5% bonus to employee whose salary is >5000 otherwise give Rs 250 as a bonus.
START
INPUT SALARY OF AN EMPLOYEE
IS SAL>=5000
BONUS=0.05*SALARY
BONUS=250
PRINT BONUS
STOP

20. Flowcharts Advantages Limitations
Communication : Flowcharts are a better way of communicating the logic of a system to all concerned
Effective Analysis: With flowcharts, problem can be analyzed more effectively.
Proper Documentation : Program flowcharts serve as a good program documentation needed for various purposes.
Efficient Coding: Flowcharts act as a guide or blueprint during the systems analysis and program development phase.
Proper Debugging: Flowcharts help in the debugging process.
Efficient Program Maintenance : The maintenance of an operating program becomes easy with the help of a flowcharts
Limitations
Complex logic: The program logic is quite complicated. In such a case, a flowchart become complex and clumsy.
Alterations and modifications: If alterations are required, the flowchart may need to be redrawn completely.
Reproduction: Since the flowcharts symbols cannot be typed in, the reproduction of a flowchart become a problem.
TEJAS MODI

21. THANK YOU