README

PHP library for data structures like Sorted Linked List

Installation

composer require sergiobelya/data-structures

Sorted Linked List

The data structure that consists of elements, each containing a link to the next element, and all elements are always kept sorted. One instance of SortedLinkedList contains int or string values but not both.

Available actions

• add
• delete
• shift
• pop
• isValueExists
• count
• reverse
• toArray
• iterate

Usages

Notice: each $value used for one instance of SortedLinkedList should be int or string but not both, otherwise \InvalidArgumentException will be thrown.

Add

use Sergiobelya\DataStructures\SortedLinkedList;

// 1 example
$list = new SortedLinkedList();
while ($value = /* some function, e.g. fetch record from DB, read row from file, pop value from array, etc. */) {
    $list->add($value);
}

// 2 example
$sortedListInt = new SortedLinkedList();
$sortedListInt->add(5);
$sortedListInt->add(15);
$sortedListInt->add(10);

// 3 example
$sortedListString = new SortedLinkedList();
$sortedListString->add('USA');
$sortedListString->add('Canada');
$sortedListString->add('Mexico');

Delete

// Delete value from SortedLinkedList<int>
$sortedListInt->delete(10);

// Delete value from SortedLinkedList<string>
$sortedListString->delete('Mexico');

Shift & Pop

$firstValue = $list->shift();
$lastValue = $list->pop();

Is Value Exists

if ($list->isValueExists('USA')) {
    // do something
}

Count

$countItems = $list->count();
// or
$countItems = count($list);

Reverse

// 1st option - call reverse() before add()
$sortedList = new SortedLinkedList();
$sortedList->reverse();
foreach ($originalData as $value) {
    // add values in descending order
    $sortedList->add($value);
}

// 2nd option - call reverse() after add()
$sortedList = new SortedLinkedList();
foreach ($originalData as $value) {
    // add values in ascending order
    $sortedList->add($value);
}
// reverse all values in descending order
$sortedList->reverse();

To Array

$data = $list->toArray();

Iterations

foreach ($list as $value) {
    // do something
}