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PHP 7 Data Structures and Algorithms

You're reading from   PHP 7 Data Structures and Algorithms Implement linked lists, stacks, and queues using PHP

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Product type Paperback
Published in May 2017
Publisher Packt
ISBN-13 9781786463890
Length 340 pages
Edition 1st Edition
Languages
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Author (1):
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Mizanur Rahman Mizanur Rahman
Author Profile Icon Mizanur Rahman
Mizanur Rahman
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Table of Contents (14) Chapters Close

Preface 1. Introduction to Data Structures and Algorithms FREE CHAPTER 2. Understanding PHP Arrays 3. Using Linked Lists 4. Constructing Stacks and Queues 5. Applying Recursive Algorithms - Recursion 6. Understanding and Implementing Trees 7. Using Sorting Algorithms 8. Exploring Search Options 9. Putting Graphs into Action 10. Understanding and Using Heaps 11. Solving Problems with Advanced Techniques 12. PHP Built-In Support for Data Structures and Algorithms 13. Functional Data Structures with PHP

Understanding recursion

Recursion is a way to solve larger problems by dividing them into smaller problems. In other words, recursion is breaking the big problem into smaller similar problems to solve them and get the actual results. Often, recursion is termed as a function calling itself. It might sound strange, but the fact is the function must call itself when it is in recursion. What does this look like? Let's look at an example,

In mathematics, the term "factorial" is very popular. A factorial of a number N is defined as multiplication of all positive integers less than and equal to N. It is always denoted with ! (an exclamation mark). So, a factorial of 5 can be written as follows:

5! = 5 X 4 X 3 X 2 X 1

Similarly, we can write the following factorials of the given number::

4! = 4 X 3 X 2 X 1

3! = 3 X 2 X 1

2! = 2 X 1

1! = 1

If we look closely at our...

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