ALGORITHMS
What are Algorithms?
Algorithms can be defined as the process or set of rules to be followed in
calculation or other problem-solving operations, especially by a computer. The
first step in every programming language is used to write an algorithm. The
algorithm is the step-by-step process for doing a task
Why do we follow the algorithm?
✓ It produces an ordered sequence of steps that provide a solution to a
problem.
✓ It is also an effective method of solving a problem using a frequency of
instructions it forms a fundamental part of Computing.
Advantages of Algorithms:
1. It is a step-wise representation of a solution to a given problem, which
makes it easy to understand.
2. An algorithm uses a definite procedure.
3. It is not dependent on any programming language, so it is easy to
understand for anyone even without programming knowledge.
4. Every step in an algorithm has its logical sequence so it is easy to debug
(spot errors).
5. By using an algorithm, the problem is broken down into smaller pieces or
steps hence, it is easier for a programmer to convert it into an actual
program.
Disadvantages of Algorithms:
1. Algorithms are Time consuming.
2. Not suitable for all problems. Difficult to show Branching and Looping in
Algorithms.
3. Big tasks are difficult to put in Algorithms as they are very timeconsuming.
Tools of algorithms
There are mainly two tools to understand the programming logic. These are:
1. Flowchart
2. Pseudocode
Flow charts
Flowcharts are a pictorial or graphical representation of algorithms.
Flowcharts use shapes symbols to represent an activity. The flow of lines with
arrows are used to depict(represent) the flow of data within a program
The various symbols used in the flowchart are given in the table below
Name
Symbol
Description
Terminator box
Oval
Represent the beginning or
end of a flowchart
Input/output box
Parallelogram
Represent the input and
output operations in a
flowchart
Process box
Rectangle
Represent the process of
instructions to be carried
out example calculation
Decision box
Diamond
This symbol is used in
branching when a decision
is to be made
Connector box
Circle
Disconnect one part of the
flowchart to another
Flow lines
This represents the flow of
information from one point
to another
Rules to be followed when writing flowchart
1. The listing of all requirements should be done in a logical order.
2. Ensure that the flowchart has a logical start and finish.
3. The flow of information in a flowchart should be from top to bottom or
from left to right.
4. Only one-floor line should come out from the process symbol.
5. In a decision symbol only one flow line should enter it where is there can
be any number of outgoing flow lines
6. The Terminator symbol can have only one flowline.
7. The connectors reduce the number of flowlines. This should be used to
make the flowchart simple. avoid intersection of long lines.
8. A flowchart should be clear and easy-to-follow
START
Collect
Leaves
Wrap the
leaves for
drying
Dry the
leaves
STOP
Advantages of flowchart
i.
ii.
iii.
The symbols are self-explanatory and easier to understand.
Graphic symbols make the process of explaining an algorithm quite
straightforward.
With the help of a flowchart problems can be analyzed more effectively.
Disadvantages of flowcharts
i.
ii.
iii.
iv.
Diagrammatic representation takes a lot of time.
Difficult to handle complex programs.
Standard rules need to be followed for making a flowchart.
If changes are required the flowchart may need to be completely
redrawn.
CHARACTERISTICS OF ALGORITHMS:
Precision – the steps are precisely stated(defined).
Uniqueness – results of each step are uniquely defined and only depend on the
input and the result of the preceding steps.
Finiteness – the algorithm stops after a finite number of instructions are
executed.
Input – the algorithm receives input.
Output – the algorithm produces output.
Generality – the algorithm applies to a set of inputs
PSEUDOCODE
It is an informal language that helps programmers to develop algorithms it is
generally written in simple English statements to represent the logic of a
program pseudocodes help a non-programmer to understand how a program
works one person’s pseudocode can differ from that of the other.