This presentation describes algorithms, flow charts and pseudocode

1. ALGORITHM, PSEUDOCODE AND FLOW CHART
BY: SATVEER KAUR, ASSISTANT PROFESSOR, KHALSA COLLEGE, PATIALA 1

2. ALGORITHM
 A finite set of steps that specify a sequence of operations to be carried out in order to solve a specific
problem.
 It consists a set of explicit and clearly defined finite steps to carry out for a given set of initial conditions,
produce the corresponding output and terminate after a fixed amount of time.
 Tells the computer to solve the problem in a systematic way to get the desired output.
BY: SATVEER KAUR, ASSISTANT PROFESSOR, KHALSA COLLEGE, PATIALA 2

3. CHARACTERISTICS OR PROPERTIES OF ALGORITHMS
 Finiteness- must terminate in finite number of steps.
 Simplicity- Should be simple and easy to read.
 Absence of Ambiguity- each step must be clear and unambiguous.
 Feasibility- each step must be simple enough that it can be easily translated into the required language.
 Completeness and correctness- must be complete and correct.
 Input-These are zero or more values which are externally supplied to the algorithm.
 Output-At least one value is produced.
BY: SATVEER KAUR, ASSISTANT PROFESSOR, KHALSA COLLEGE, PATIALA 3

4. STEPS TO WRITE ALGORITHM
 Start the algorithm.
 Take input from user.
 Process the input data.
 Produce one or more results after processing.
 Show the result.
 Exit the algorithm.
BY: SATVEER KAUR, ASSISTANT PROFESSOR, KHALSA COLLEGE, PATIALA 4

5. VERIFYING THE ALGORITHMS
 To ensure the efficient execution of program, it is necessary to verify the algorithm before converting it
into a computer program.
 Different methods to verify are:
 Dry run: find the value of each variable manually after every step.
 Review: studying the logic and computing with a specification.
 Walk through: presented to the team member for checking the efficiency.
BY: SATVEER KAUR, ASSISTANT PROFESSOR, KHALSA COLLEGE, PATIALA 5

6. EXAMPLE FOR AN ALGORITHM
 Add two numbers.
 Step 1: Start algorithm.
 Step 2: Enter two numbers a, b.
 Step 3: Compute c = a + b.
 Step 4: Print c.
 Step 5: Exit.
BY: SATVEER KAUR, ASSISTANT PROFESSOR, KHALSA COLLEGE, PATIALA 6

7. FLOW CHART
 A pictorial representation of problem and algorithms to its solution that uses the symbols connected by
flow lines.
 Called flow chart because it charts the flow of program.
 Used in expressing and understanding algorithms.
 Useful for the programmer and system analyst.
BY: SATVEER KAUR, ASSISTANT PROFESSOR, KHALSA COLLEGE, PATIALA 7

8. SYMBOLS USED FOR FLOW CHART
 The terminator symbol:
 represented by rectangle by rounded ends.
 Indicates the start and stop of the flow chart.
 Input output symbol:
 Represented by parallelogram.
 Indicates input output operation.
BY: SATVEER KAUR, ASSISTANT PROFESSOR, KHALSA COLLEGE, PATIALA 8

9. SYMBOLS USED FOR FLOW CHART
 Decision symbol:
 Represented by diamond.
 Used to check the conditions whether true or false.
 Depending upon the condition, the program branches into direction.
 Process symbol:
 Represented by rectangle.
 Indicates any processing, operation, calculation etc.
BY: SATVEER KAUR, ASSISTANT PROFESSOR, KHALSA COLLEGE, PATIALA 9

10. SYMBOLS USED FOR FLOW CHART
 Connector symbol:
 Represented using a circle.
 Brings together two branches of a program.
 Connects various pages of long flow charts.
 Predefined Process symbol:
 Represented using process symbol ( rectangle with two lines one on left and one on right side).
 Indicates a module of a program already defined by another flow chart.
BY: SATVEER KAUR, ASSISTANT PROFESSOR, KHALSA COLLEGE, PATIALA 10

11. SYMBOLS USED FOR FLOW CHART
 Document symbol:
 Represented by document symbol.
 Used to represent any document on paper.
 Data flow symbol:
 Represented by arrows.
 Indicates the flow of operation.
 Also connects other symbols to one another.
BY: SATVEER KAUR, ASSISTANT PROFESSOR, KHALSA COLLEGE, PATIALA 11

12. SYMBOLS USED FOR FLOW CHART
 Annotation symbol:
 Represented by open-ended box connected to the chart by dotted lines.
 Used for explanation or comments related to the program.
 Preparation:
 Represented by hexagon.
 Used to control, initiate or perform some other operation on the program itself.
BY: SATVEER KAUR, ASSISTANT PROFESSOR, KHALSA COLLEGE, PATIALA 12

13. PSEUDOCODE
 Consists of short, English phrases used to explain specific tasks within a program.
 Is an informal high level description of the operating principle of a program or an algorithm.
 Should not include keywords in any specific computer language.
 Should be written as a list of consecutive phrases.
 allows the designer to focus on the logic of the algorithm without being distracted by details of
language syntax.
 describe the entire logic of the algorithm.
BY: SATVEER KAUR, ASSISTANT PROFESSOR, KHALSA COLLEGE, PATIALA 13

14. EXAMPLE OF PSEUDOCODE
 Write a pseudocode to find sum and average of given two numbers.
 Begin
 WRITE “Please enter two numbers to add”
 READ num1
 READ num2
 Sum = num1+num2
 Avg = Sum/2
 WRITE Sum, Avg
 End
BY: SATVEER KAUR, ASSISTANT PROFESSOR, KHALSA COLLEGE, PATIALA 14

15. THANKS !!!!!!!!
BY: SATVEER KAUR, ASSISTANT PROFESSOR, KHALSA COLLEGE, PATIALA 15