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Algorithms Tutorial

Last Updated : 01 May, 2024
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Algorithm is a step-by-step procedure for solving a problem or accomplishing a task. In the context of data structures and algorithms, it is a set of well-defined instructions for performing a specific computational task. Algorithms are fundamental to computer science and play a very important role in designing efficient solutions for various problems. Understanding algorithms is essential for anyone interested in mastering data structures and algorithms.

What is Algorithm?

What is an Algorithm?

An algorithm is a finite sequence of well-defined instructions that can be used to solve a computational problem. It provides a step-by-step procedure that convert an input into a desired output.

How do Algorithms Work?

Algorithms typically follow a logical structure:

  • Input: The algorithm receives input data.
  • Processing: The algorithm performs a series of operations on the input data.
  • Output: The algorithm produces the desired output.

Characteristics of an Algorithm:

  • Clear and Unambiguous:  The algorithm should be unambiguous. Each of its steps should be clear in all aspects and must lead to only one meaning.
  • Well-defined Inputs: If an algorithm says to take inputs, it should be well-defined inputs. It may or may not take input.
  • Well-defined Outputs: The algorithm must clearly define what output will be yielded and it should be well-defined as well. It should produce at least 1 output.
  • Finiteness: The algorithm must be finite, i.e. it should terminate after a finite time.
  • Feasible: The algorithm must be simple, generic, and practical, such that it can be executed using reasonable constraints and resources.
  • Language Independent: Algorithm must be language-independent, i.e. it must be just plain instructions that can be implemented in any language, and yet the output will be the same, as expected.

What is the Need for Algorithms?

Algorithms are essential for solving complex computational problems efficiently and effectively. They provide a systematic approach to:

  • Solving problems: Algorithms break down problems into smaller, manageable steps.
  • Optimizing solutions: Algorithms find the best or near-optimal solutions to problems.
  • Automating tasks: Algorithms can automate repetitive or complex tasks, saving time and effort.

Examples of Algorithms

Below are some example of algorithms:

  • Sorting algorithms: Merge sort, Quick sort, Heap sort
  • Searching algorithms: Linear search, Binary search, Hashing
  • Graph algorithms: Dijkstra’s algorithm, Prim’s algorithm, Floyd-Warshall algorithm
  • String matching algorithms: Knuth-Morris-Pratt algorithm, Boyer-Moore algorithm

How to Write an Algorithm?

To write an algorithm, follow these steps:

  • Define the problem: Clearly state the problem to be solved.
  • Design the algorithm: Choose an appropriate algorithm design paradigm and develop a step-by-step procedure.
  • Implement the algorithm: Translate the algorithm into a programming language.
  • Test and debug: Execute the algorithm with various inputs to ensure its correctness and efficiency.
  • Analyze the algorithm: Determine its time and space complexity and compare it to alternative algorithms.

Learn Basics of Algorithms

Analysis of Algorithms

Types of Algorithms

Algorithms can be different types, depending on what they do and how they’re made. Some common types are:

1. Searching and Sorting Algorithms

2. Greedy Algorithms

3. Dynamic Programming Algorithms

4. Pattern Searching Algorithms

5. Backtracking Algorithm

6. Divide and Conquer Algorithm

7. Geometric Algorithm

8. Mathematical Algorithms

9. Bitwise Algorithms

10. Graph Algorithms

11. Randomized Algorithms

12. Branch and Bound Algorithms


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