# What Is An Algorithm? Characteristics, Types, and How to write it

An avid programmer, very well knows that algorithms play an important role in solving technical problems and processing data. The important thing to note about algorithms is that you will have to learn about its characteristics and types before you can start the procedure for writing the algorithm.

In this blog, we have brought to you all the information you need to know as a beginner programmer to learn the concept of algorithms.

From the types of algorithms to the time complexity of sorting algorithms, we have incorporated all the details. Henceforth, you are urged to read till the end of the blog.

## What is an algorithm?

Before learning the book definition of algorithm let us clarify an important fact about the subject. Algorithms are basically used in all the different fields and are in no way restricted to the field of computer science.

Algorithms can be defined as finite sets of instructions that are used to solve a given problem.

An algorithm is a sequence of instructions that are used to find the end result for a problem.

Algorithms should not be confused with the concept of programming. In order to design software or a program, the algorithm is mentioned prior to programming.

After knowing the basics of the algorithm, it is essential to know about its characteristics for a better understanding on the topic.

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### Characteristics of Algorithms

In the context of algorithms, the steps followed for completing the algorithm are referred to as sequences.

But, keep in mind that not all procedures can be considered algorithms.

The sequences must depict the following characteristics in order to qualify as algorithms:

- Unambiguous

The book definition for the word is something that leads in a single direction or something that has a single meaning.

In the context of algorithms, the sequences of steps followed to complete the problem must lead to a definite output. The end result for the problem should point in a single direction.

**Input**

Algorithms are characterized by having 0 or similar inputs which should be definitive in order to form a proper output for the problem.

**Output**

The output for any algorithm should have 1 or more definitive output. It should always match the desired level of output that the programmer has been looking to attain.

**Finiteness**

This characteristic shares similarity with the characteristic of unambiguity. As we have discussed earlier with an example, the sequences for an algorithm must have a finite number of steps after which the algorithm will terminate.

**Feasibility**

The procedure of the algorithm should be attainable or feasible. This simply means that neither the input statements nor the output of the algorithm should be outside of our reach.

**Independent**

The sequences for an algorithm or the step by step procedure must be predefined before the programmers proceed with the process of defining the programming code.

Those were the major criterias that the sequences for an algorithm must follow in order to be eligible for forming an algorithm.

Now before learning how you can compute an algorithm let us take a look at the types of algorithms to get a general idea.

### What are the types of algorithms?

From brute force algorithm to recursive algorithm, there are **various type of algorithms** which are discussed as follows: :

#### Brute force algorithm

The brute force algorithm basically iterates all the possible sequences that you can follow in order to solve the given problem at hand and produce an output. The brute force algorithm is considered to be one of the most basic forms of algorithms. This algorithm is used in the 4-digit Pins for banking cards.

#### Recursive algorithm

These sort of algorithms are solved by breaking the input statements or the sequences into smaller bits following the recursion process. This makes it easier to attain the desired output for the algorithm. The M coloring problem or the Maze problem uses a recursive algorithm.

#### Randomised algorithm

More like in the process of finding a median in mathematics, the random algorithm follows a similar framework. Here we randomly choose a number that further indicates the desired output. The randomised algorithm is used in Quicksort.

#### Sorting algorithm

This is one of the most interesting processes for deriving algorithms. Here the input is sorted into ascending or descending order before writing the algorithm. For instance bubble sort and merge sort algorithms.

#### Searching algorithm

This sort of algorithm is used for searching a specific kind of key in sorted or unsorted data. The binary search and other common problems are solved using this algorithm.

#### Hashing algorithm

The hashing algorithm is similar to the searching type except for the keys here have a specific value known as the key-value pair or key ID. This sort of algorithm is used in the verification of the passwords.

Now that you might be familiar with the types of algorithms and their uses, let us discuss the steps you can employ for writing an algorithm.

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#### How to write an algorithm?

The procedure for writing an algorithm is not structured or defined as you would think. Algorithms are resource and problem adaptive.

What we are trying to clear is that the algorithms are written based on the complexity and type of problem that we have been given.

Loops such as while, for, and do, and flow-control such as if-else are used for writing the algorithm.

Also, algorithms are never written to manipulate the program and we must have a problem domain to write the algorithm.

Finally, the time complexity for solving algorithms is calculated based on the logarithm of the input or the size of the data that is in log (n).

#### Wrapping Up

From PINS of our bank credentials to password-protected accounts, algorithms hold such complex information in an easy format.

Although the **time complexity for solving algorithms** may depend on the types of algorithms, one thing to keep in mind is that algorithms and programs are two different constructs.