Created
September 8, 2015 12:40
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<?php | |
class SingleLinkedListNode | |
{ | |
public $value, $next; | |
public function __construct($value = NULL) | |
{ | |
$this->value = $value; | |
} | |
} | |
/** | |
* Removes a node from a single linked list | |
* | |
* @param \SingleLinkedListNode $node | |
* | |
* @return bool Returns false if the node is the tail, true otherwise | |
*/ | |
function removeNode(SingleLinkedListNode $node) | |
{ | |
if (!$node->next) { | |
return FALSE; | |
} | |
$node->value = $node->next->value; | |
$node->next = $node->next->next; | |
return TRUE; | |
} | |
/* Usage */ | |
// Handcraft a linked list | |
$nodes = []; | |
foreach (range(5, 1, -1) as $val) { | |
$node = new SingleLinkedListNode($val); | |
if ($val !== 5) { | |
$node->value = $val; | |
$node->next = $nodes[$val + 1]; | |
} | |
$nodes[$val] = $node; | |
} | |
extract($nodes, EXTR_PREFIX_ALL, 'node'); | |
// Now we have 1 -> 2 -> 3 -> 4 -> 5 | |
// with nodes in variables named $node_1, $node_2, etc. | |
// Remove a node | |
removeNode($node_3); | |
// Let's traverse the list | |
$node = $node_1; | |
do { | |
echo $node->value; | |
if ($node->next) { | |
echo ' -> '; | |
$node = $node->next; | |
} else { | |
break; | |
} | |
} while (TRUE); | |
/* | |
1 -> 2 -> 4 -> 5 | |
Congratulations :) | |
$node_2 has value of 2 and points to $node_3 | |
$node_3 has value of **4** and points to **$node_5** | |
*/ |
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