Algorithms and Pseudocode Basics

Algorithms

• Algorithms are processes or sets of rules followed in calculations or problem-solving operations
• They are sets of rules/instructions that define how a task is executed step-by-step to achieve the desired outcome
• Algorithms can be understood through examples like following a cooking recipe
• Algorithms help programmers do tasks to get the expected outputs in programming

Pseudocode

• Pseudocode is a simplified way of writing programming code using English phrases
• It's a stepping stone before writing actual code in a specific programming language
• It's helpful for outlining program logic before implementation.
• Pseudocode examples can cover adding numbers and calculating rectangular area.

Characteristics of an Algorithm

• Clear and Unambiguous: Algorithm steps must be clear and unambiguous, having only one interpretation

• Well-Defined Inputs: Inputs must be clearly defined if required by the algorithm

• Well-Defined Outputs: The output expected by the algorithm must be explicitly defined

• Finite: The algorithm must have a finite number of steps and not result in infinite loops

• Feasible: The algorithm must be simple, practical and executeable using the available resources.

• Language Independent: The algorithm's design should be language-independent which means it can be implemented in any programming language.

Advantages of Algorithms

• Algorithms help understand the problem clearly
• They represent a step-by-step solution to a given problem
• Breaking down problems into smaller steps simplifies converting these solutions into actual programs.

How to Design an Algorithm

• Understand the problem to be solved.
• Identify constraints on solving the problem.
• Define the input needed for problem solving
• Decide on the expected output for the problem solution in reference to the given constraints
• Describe a solution to the problem in consideration to these constraints.

Example: Add 3 Numbers

• Problem: Adding three numbers and displaying their sum
• Constraints: Input numbers are digits only.
• Input: Three numbers (e.g., num1, num2, num3)
• Output: Sum of the three input numbers
• Solution: Add the three numbers using the addition operator or a similar method.

Designing the Algorithm to add 3 numbers

• Declare variables to store three numbers, (num1, num2, num3).
• Declare one more variable sum.
• Take input of the three numbers one by one and store in declared variables.
• Add the three numbers and store the result in the 'sum' variable.
• Print the value of 'sum' variable..