1. Dr. Jeetashree Aparajeeta
Assistant Professor (Sr)
SENSE

2.  Introduction to Problem Solving
◦ Problem Solving: Definition and Steps
◦ Problem Analysis Chart
◦ Developing an Algorithm
◦ Flowchart
◦ Pseudocode
2

3.  Use of computer technology help in completing any
task in a much faster and accurate manner.
 Ex. Paying electric bill, booking a health check up,
ordering your favorite food, booking movie tickets
etc.
 These technologies follow a proper problem
solving approach for an essential skill to solve the
related problems.
 Ex. You cannot order food using Apollo247 App.
3

4.  The standard computers, that we use, are not
advance enough to solve a problem of their own,
so we need to feed step-by-step instructions to
the computer to solve any problem.
 The efficiency in solving the problem depends
upon how correctly and precisely we define the
problem, design a solution (algorithm) and
implement the solution (program) using a
programming language.
4

5.  So, the problem solving can be defined as the
process of identifying a problem, developing an
algorithm for the identified problem and finally
implementing the algorithm to develop a
computer program.
5

6.  The correctness of the output that a computer gives
depends upon the correctness of input provided.
 Key steps required for solving a problem
I. Analyzing the problem
II. Developing an algorithm
a. Flowchart
b. Pseudocode
III. Coding
IV. Testing and Debugging
6

8. Analysing the problem
It is important to clearly understand a problem before
we begin to find the solution for it. If we are not clear
as to what is to be solved, we may end up developing
a program which may not solve our purpose. Thus,
we need to read and analyse the problem statement
carefully in order to list the principal components of
the problem and decide the core functionalities that
our solution should have. By analysing a problem, we
would be able to figure out what are the inputs that
our program should accept and the outputs that it
should produce

9. 4.2.1 Analysing the problem
It is important to clearly understand a problem before
we begin to find the solution for it. If we are not clear
as to what is to be solved, we may end up developing
a program which may not solve our purpose. Thus,
we need to read and analyse the problem statement
carefully in order to list the principal components of
the problem and decide the core functionalities that
our solution should have. By analysing a problem, we
would be able to figure out what are the inputs that
our program should accept and the outputs that it
should produce.

10. 4.2.2 Developing an Algorithm
It is essential to device a solution before writing a
program code for a given problem. The solution is
represented in natural language and is called an
algorithm. We can imagine an algorithm like a very
well-written recipe for dish.
We start with a tentative solution plan and keep
on refining the algorithm until the algorithm is able
to capture all the aspects of the desired solution. For
a given problem, more than one algorithm is possible
and we have to select the most suitable solution

11.  4.2.3 Coding
 After finalising the algorithm, we need to
convert the algorithm into the format which
can be understood by the computer to
generate the desired solution. Different
 high level programming languages can be
used for writing a program

12. 4.2.4 Testing and Debugging
The program created should be tested on
various parameters. The program should meet
the requirements of the user. It must respond
within the expected time. It should generate
correct output for all possible inputs. In the
presence of syntactical errors, no output will
be obtained. In case the output generated is
incorrect, then the program should be checked
for logical errors, if any.

33. 33
Separate the problem into
three components
Input
A list of data source
Provided to the problem
Output
A list of the output
required
Processing
A list of actions needed
to produce the required
outputs.

34.  PAC is used to analyze a problem.
 It has four sections:
a. The given data
b. The required result
c. The processing involved
d. A list of solution alternative
34

35. Given Data Required result
Section 1
Data given in the
problem/ provided by the
user
Section 2
Requirements for the
output reports including
the information needed
and the format required
Processing Required Solution Alternative
Section 3
List of processing
required including
equations or other types
of processing.
Section 4
List of ideas for the
solution of the problem
35

36.  Problem:
 A program is required to find average of five
numbers.
36

37. 37
Given Data Required result
Number 1
Number 2
Number 3
Number 4
Number 5
Average of 5 numbers
Processing Required Solution Alternative
Total = Number 1 +
Number 2 + Number 3 +
Number 4 + Number 5
Average = Total / 5
i. Define the numbers as
constants
ii. Define the numbers as
input values

38.  Total = 5 + 6 + 8 + 9 + 11
Or
 Number 1 = 5, Number 2 = 6, Number 3 = 8,
Number 4 = 9, Number 5 = 11
Or
 Number = “Ask the user to provide the
number”
38

39.  Calculate the gross pay of an employee. The
formula to be used : GrossPay = Hours x
Payrate
39

40. 40
Given Data Required result
Hours
PayRate
Gross Pay
Processing Required Solution Alternative
GrossPay = Hours * PayRate 1. Define the hours worked and
Payrate as constant
2. Define the hours worked and
PayRate as input

41.  Convert the distance in KM to miles where 1
mile = 1.609 km
41

42. 42
Given Data Required result
Distance in km Distance in mile
Processing Required Solution Alternative
Mile = km/1.609 1. Define the km as constant
2. Define the km as input

43.  An algorithm is an effective method expressed as
a finite list of well defined instructions for
calculating a function, starting from an initial
state and initial input.
 The instructions describe a computation, which
will eventually produce output, when executed.
 Algorithm can be used to solve any kind of
problems.
 However, before writing a program, we need to
write the steps to solve the problem in simple
English language. This step-by-step procedure
to solve the problem is called algorithm.
43

44.  The way of execution of program is
categorized as
◦ Sequence Statements
◦ Selection Statements
◦ Iteration or Looping Statements (Called Control
Structure)
44

45.  In this program, all the instructions are
executed one after another.
 Ex: Algorithm to find the area of a rectangle
◦ Step 1: Start
◦ Step 2: Take length and breadth and store them as
L and B
◦ Step 3: Multiply by L and B and store it in Area
◦ Step 4: Print Area
◦ Step 5: Stop
45

46.  In this type of programming, some portion of
the program is executed based upon the
conditional test.
 If the conditional test is true, compiler will
execute some part of the program, otherwise
it will execute the other part of the program.
46

47.  Ex: Algorithm to check whether a candidate is
eligible to vote?
◦ Step 1: Start
◦ Step 2: Take age and store it in Age
◦ Step 3: Check Age value, if age > 18, then go to
step-4 else Step-5
◦ Step 4: Print “Eligible to Vote” and go to Step-6
◦ Step 5: Print “Not Eligible to Vote”
◦ Step 6: Stop
47

48.  Two common methods are used to represent
an algorithm
a. Flowchart
b. Pseudocode
 Either of the methods can be used to represent
an algorithm.
48

49.  The flowchart and pseudocode showcases the
logic of the solution required to solve the
problem excluding any implementation details.
 We can understand the flow of control during
execution of the program.
49

50.  Visual representation of an algorithm
 It is a diagram made up of boxes, diamonds
and other shapes, connected by arrows.
 Each shape represents a step of the solution
process and the arrow represents the order or
link among the steps.
50

51. A flow chart is an
organized
combination of shapes,
lines and text that
graphically illustrate a
process or structure.
51

52.  Write an algorithm to find the square of a
number
52

53.  Before developing the algorithm, first identify
the input, process and output.
◦ Input: Number whose square is required
◦ Process: Multiply the number by itself to get its
square
◦ Output: Square of the number
53

54.  Step 1: Input a number and stored it to Number
(Number is a variable)
 Step 2: Compute Number * Number and store it
in Square (Square is a variable)
 Step 3: Print Square
54

55. 55

56. 56

57.  Pseudocode is another way of representing an algorithm.
 It is a kind of structured English for describing algorithms
 It allows the designer to focus on the logic of the algorithm
without being distracted by details of language syntax
 Pseudocode needs to be complete
 It describe the entire logic of the algorithm so that
implementation becomes a rote mechanical task of
translating line by line into source code
57

58.  Each instruction is written on a separate line
 Keywords and indentation are used to signify
particular control structures
 Each set of instructions is written from top to
bottom, with only one entry and one exit
 Groups of statements may be formed into modules,
and that group given a name.
58

59.  Several keywords are often used to indicate
common input, output, and processing
operations
 Input: READ, OBTAIN, GET
 Output: PRINT, DISPLAY, SHOW
 Compute: COMPUTE, CALCULATE, DETERMINE
 Initialize: SET, INIT
 Add one: INCREMENT, BUMP, DECREMENT
59

60.  Area of Rectangle.
60

61.  READ height of Rectangle
 READ width of Rectangle
 COMPUTE area as height times width
 PRINT area of rectangle
61

63.  Format
IF Condition THEN
Statements
ELSE
Statement
ENDIF
 Example
IF Hours_Worked > Normal_Max THEN
Display overtime message
ELSE
Display regular time message
ENDIF
63

64.  Format
WHILE Condition
Statements
ENDWHILE
 Example
WHILE Population < Limit
Compute Population as Population + Births ‐ Deaths
ENDWHILE
64

65.  Format
FOR Iteration Bounds
Statements
ENDFOR
 Example
FOR each student in the list
Print Register_Number
ENDFOR
65

67. 67