Characteristics of an algorithm with examples and explanations

🧑‍💻 By quescol • 📝 Updated on: 17 July 2025

An algorithm is a step-by-step procedure designed to solve a specific problem. But just writing an algorithm is not enough. To be useful and efficient, the algorithm must follow certain rules and exhibit specific characteristics.

Here we will learn the key characteristics of a good algorithm, along with real-world examples.

As we know that, algorithms provide us the procedure to solve any problem.

Characteristics of a good algorithm

• Independent – Any algorithm developed should be written in such a way that it is easily understood and can be implemented on any programming language. This is called language independence and  a good algorithm is always independent of the programming language.
• Input – When the user is asked to input something from his side that should be easily understandable as what the input is (i.e. character or integer or a decimal number). If there is a program that does not need any user input like pattern programs then such programs should directly produce output without prompting/asking the user to input something.

• Output – After taking some inputs from the end-user algorithm should produce an output based on the provided input. The output to be produced should be well defined in the algorithm.
• Finiteness -Any algorithm must be designed in such a way that it should produce output in a finite amount of time. It should not run for infinite time. The output should be produced within a few seconds.
• Unambiguous – The steps defined in an algorithm should be very clear and unambiguous. As it should convey clear meaning in the steps and should not make any confusion to the one who is reading it.
• Feasible – The algorithm developed should be applicable with  the current technology and available resources. It should be workable with the present technology and should not contain any future technology reference.

Every algorithm developed today is measured on the above-defined matrices and it should be considered while designing a new algorithm.

What Makes an Algorithm “Good”? [Detailed Explanations]

Not every set of instructions is a good algorithm. A well-designed algorithm should be clear, effective, efficient, and practical. Let’s look at the most important characteristics every good algorithm should have:

1. Language Independent

A good algorithm should be independent of any specific programming language. It should be written in a way that it can be easily implemented in C, Java, Python, or any other language.

✅ Example:

If your algorithm says:

Step 1: Add two numbers
Step 2: Display the result

This can be written in any language and will give the same output. That’s language independence.

Why it matters: It ensures portability and allows developers to implement the same logic across various platforms or technologies.

2. Input Should Be Clearly Defined

Every algorithm may or may not require inputs. If inputs are needed, they must be well defined, clear, and specific. The algorithm should state:

• What inputs are needed?
• What data type they should be (integer, float, character)?
• Are they coming from the user or a fixed source?

Example:

If the algorithm needs two numbers to be added, it must clearly state:

Input: Two integers, num1 and num2

Why it matters: This avoids confusion and makes the algorithm easier to implement and test.

3. Output Should Be Well Defined

A good algorithm must always produce at least one well-defined output that is based on the given input.

Example:

For an algorithm that adds two numbers, the output must be:

Output: Sum of num1 and num2

Why it matters: Without output, the algorithm has no purpose or measurable result.

4. Finiteness

An algorithm must complete after a finite number of steps. It should not go into an infinite loop or hang indefinitely.

Example:

A loop that runs exactly 10 times is finite. But a loop with the condition while(true) without a break is infinite unless managed carefully.

Why it matters: An algorithm that doesn’t stop is useless and wastes resources.

5. Unambiguous (Clarity of Steps)

Every step in the algorithm must be clear, simple, and unambiguous. Anyone reading the algorithm should understand what each step means without needing extra explanation.

❌ Bad Step:

Step 3: Process the input

✅ Good Step:

Step 3: Multiply input number by 2 and store in variable result

Why it matters: Clear instructions prevent confusion and reduce errors during implementation.

6. Feasibility

A good algorithm should be practical and feasible to implement using available technology and resources. It should not require future tech, unrealistic hardware, or inaccessible data.

✅ Example:

An algorithm requiring a quantum computer in a college project today is not feasible. But one that works with a basic desktop computer is.

Why it matters: Feasibility ensures the algorithm can actually be used in real-life applications.

Bonus: Efficient and Optimized

While not always mandatory, a great algorithm also aims to be:

• 🔄 Efficient: It uses minimal time and memory.
• ♻️ Reusable: Can be adapted for similar tasks.
• 🔍 Easy to debug: Easy to test and maintain over time.

Summary Table: Characteristics of a Good Algorithm

Characteristic	Description
Language Independent	Can be implemented in any programming language
Input	Clearly defines required inputs and data types
Output	Provides a clear and expected output
Finiteness	Terminates after a limited number of steps
Unambiguous	Every instruction is clearly defined without confusion
Feasible	Can be executed using current technology and available resources

Conclusion

To design an efficient and effective algorithm, you must ensure it meets all the above characteristics. These traits not only help in writing better code but also make debugging, testing, and maintenance easier.

Next time you write an algorithm, remember: it’s not just about solving the problem — it’s about solving it clearly, efficiently, and practically.

FAQs

❓ Why is finiteness important in an algorithm?

Finiteness ensures that the algorithm stops and gives an output in a reasonable amount of time.

❓ What is the difference between input and output in an algorithm?

Input is the data provided to the algorithm, while output is the result it produces after processing the input.

❓ Can an algorithm work without input?

Yes, some algorithms, like pattern printing, do not need user input. They still follow a defined process to generate output.