ALGORITHM
An algorithm is a set of instructions, sometimes called a procedure or a function that is used to perform a certain task.
Characteristics of an Algorithm
- Finiteness: An algorithm terminates after a finite numbers of steps.
- Definiteness: Each step in algorithm is unambiguous. This means that the action specified by the step cannot be interpreted (explain the meaning of) in multiple ways & can be performed without any confusion.
- Input: An algorithm accepts zero or more inputs
- Output: It produces at least one output.
- Effectiveness: It consists of basic instructions that are realizable. This means that the instructions can be performed by using the given inputs in a finite amount of time.
FLOWCHART
A flowchart is a type of diagram that represents an algorithm or process, showing the steps as boxes of various kinds, and their order by connecting these with arrows. This diagrammatic representation can give a step-by-step solution to a given problem. Process operations are represented in these boxes, and arrows connecting them represent flow of control.
ADVANTAGES OF FLOWCHART
- It provides an easy way of communication because any other person besides the programmer can understand the way they are represented.
- It represents the data flow.
- It provides a clear overview of the entire program and problem and solution.
- It checks the accuracy in logic flow.
- It documents the steps followed in an algorithm.
- It provides the facility for coding.
- It provides the way of modification of running program.
- They show all major elements and their relationship.
LIMITATION OF FLOW CHARTS
- It is the total perception of the designer who drawn the flowchart.
- It is working differ from one compiler to another, one language to another in some time.
- It needs well – defined requirements.
- Its basically for structured programming.
BASIC FLOW CHART SYMBOLS
Data flows are not typically represented in a flowchart, in contrast with data flow diagrams; rather, they are implied by the sequencing of operations. Flowcharts are used in analyzing, designing, documenting or managing a process or program in various fields.
FLOWCHART EXAMPLES
1) Draw a flowchart to find the sum of first 50 natural numbers.
Answer: The required flowchart is given below:
2) Draw a flowchart to find the largest of three numbers A, B, and C.
Answer: The required flowchart is shown below:
3) Draw a flowchart for computing factorial
N (N!)
Where N! =1*2*3 *…. N
Answer: The required flowchart is shown below:
4) Draw the Flow Chart and algorithm for Area and circumference of a Circle Formula:
(i) Area = πr²
(ii) Circumference = 2πr
(iii) r = radius of the circle.
Algorithm:
(i) Begin
(ii) Input r
(iii) Area = π* r* r
(iv) Circumference= 2 * π * r
(v) Output Area, Circumference
(vi) End
Flow Chart:
(5) Draw the Flow Chart and algorithm for Product of first n natural numbers
Algorithm:
Begin
product = 1
for i = 1 to n
Begin
product = product * i
End
Output product
End
Flow Chart:
6) Flow Chart for Factorial
Algorithm and flowchart to find the factorial of a given number
Factorial of 5 = 1*2*3*4*5=120
Algorithm:
(i) Begin
(i) Input N
(iii) Fact = 1
(iv) for i = 1 to N
(v) Begin
(vi) Fact = Fact *i
(vii) End
(viii) Output Fact
(ix) End
Flow chart
7) Draw flow chart to take a decision on when to replace a bad lamp.
Answer: