Characteristics of Algorithms

Input

• Algorithms can take zero or more inputs.
• Input is necessary but not mandatory for every algorithm.
• Example: Like a C language function which may not take parameters but does something.

Output

• Algorithms must generate at least one output.
• Output is essential for the usability of the algorithm.
• It's analogous to a function that must return some result, even if it's void.

Definiteness

• Each statement in an algorithm should be unambiguous and have a single, exact meaning.
• Statements should be clear and understandable so that they can be solved.
• Example: You cannot use values that are imaginary (like root minus 1) without defining them properly.

Finiteness

• An algorithm must have a finite number of steps and terminate at some point.
• Algorithms are different from services like database or web servers which run continuously.
• Example: A function with limited steps that stops and returns a result.

Effectiveness

• Each statement in the algorithm should serve a purpose and do something useful.
• Avoid unnecessary steps in the algorithm, similar to procedures in experiments or cooking recipes.

Analogies to Understand Characteristics

• Procedure Example: Chemistry or physics experiments, and cooking recipes.
  • Input: Chemicals for experiments, instruments for physics, ingredients for cooking.
  • Output: A solution in experiments, a prepared dish in cooking.
  • Definiteness: Known steps, no magic.
  • Finiteness: Procedure stops at some point.
  • Effectiveness: Only necessary steps are performed.