What is algorithm?
An algorithm is a step‑by‑step set of instructions that tells a computer (or a person) how to solve a problem or complete a task, just like a recipe tells you how to bake a cake.
Let's break it down
Think of an algorithm as a list:
- Input: the information you start with (e.g., a list of numbers).
- Steps: clear, ordered actions to process the input (e.g., compare two numbers, swap them if needed).
- Output: the result you get after all steps are done (e.g., the numbers sorted from smallest to largest).
Why does it matter?
Algorithms make sure tasks are done correctly, efficiently, and consistently. Without them, computers wouldn’t know how to search the web, play videos, or even add two numbers together.
Where is it used?
- Searching: Google’s search engine.
- Sorting: arranging your photos by date.
- Navigation: GPS route planning.
- Security: encrypting messages.
- Everyday apps: recommending videos, filtering spam, processing payments.
Good things about it
- Predictable results: same input always gives the same output.
- Speed: well‑designed algorithms can finish tasks in seconds instead of minutes.
- Reusability: the same algorithm can be used in many different programs.
- Scalability: they can handle small or huge amounts of data with minor tweaks.
Not-so-good things
- Complexity: some algorithms are hard to understand or write correctly.
- Resource use: a poorly chosen algorithm can waste memory or CPU time.
- Over‑optimization: trying to make an algorithm “perfect” can add unnecessary complexity.
- Bias: if the input data is biased, the algorithm’s output can be unfair or inaccurate.