BCE Unit – II : Introduction to Algorithms

Clear and Unambiguous (past): Algorithm should be unambiguous. Each of its steps should be clear in all aspects and must lead to only one meaning.

Well-Defined Inputs: If an algorithm says to take inputs, it should be well-defined inputs.

Well-Defined Outputs: The algorithm must clearly define what output will be yielded and it should be well-defined as well.

Finite-ness: The algorithm must be finite, i.e. it should not end up in an infinite loop or similar.

Feasible (Shambhav): The algorithm must be simple, generic, and practical, such that it can be executed upon the available resources. It must not contain some future technology or anything.

Language Independent: The Algorithm designed must be language-independent, i.e. it must be just plain instructions that can be implemented in any language, and yet the output will be the same, as expected.

Example: Consider the example to add three numbers and print the sum.

Algorithm to add 3 numbers and print their sum:

• START
• Declare 4 integer variables a, b, c, d.
• Take the three numbers, to be added, as inputs in variables a, b, and c
• Add the 3 numbers and store the result in the variable
• Print the value of d
• END

a = 3, b = 4, c = 5

Add = 3 + 4 + 5

resulted = 12

Advantages of Algorithms:

• It is easy to understand.
• The algorithm is a step-wise representation of a solution to a given problem.
• In an Algorithm the problem is broken down into smaller pieces or steps hence, it is easier for the programmer to convert it into an actual program.

Disadvantages of Algorithms:

• Writing an algorithm takes a long time so it is time-consuming.
• Branching and Looping statements are difficult to show in Algorithms.