PHP 8.5.0 Alpha 2 available for testing

La classe SplMinHeap

(PHP 5 >= 5.3.0, PHP 7, PHP 8)

Introduction

La classe SplMinHeap fournit une interface pour un tas, qui conserve le minimum sur le haut.

Synopsis de la classe

class SplMinHeap extends SplHeap {
/* Méthodes */
protected compare(mixed $value1, mixed $value2): int
/* Méthodes héritées */
protected SplHeap::compare(mixed $value1, mixed $value2): int
public SplHeap::insert(mixed $value): true
public SplHeap::key(): int
}

Sommaire

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User Contributed Notes 2 notes

up
3
gom
5 years ago
I experimented what happens when arrays are inserted:

<?php
$heap
= new SplMinHeap();
$heap->insert([22,333]);
$heap->insert([2,33]);
$heap->insert([222,3]);

var_export($heap->extract());
echo
'<br>';
var_export($heap->extract());
echo
'<br>';
var_export($heap->extract());
?>

Output:

array ( 0 => 2, 1 => 33, )
array ( 0 => 22, 1 => 333, )
array ( 0 => 222, 1 => 3, )
up
0
andy at nospam dot airslash dot net
10 days ago
To expand on gom's comment, SplMinHeap will also take into account the subsequent elements of the array you inserted, if the elements before that are equal.

<?php
$heap
= new SplMinHeap();
$heap->insert([0, 10]);
$heap->insert([0, 30]);
$heap->insert([0, 15]);
while (!
$heap->isEmpty()) {
[
$a, $b] = $heap->extract();
echo
"a:$a, b:$b\n";
}
echo
"---\n";
$heap->insert([0, 10, 100]);
$heap->insert([0, 10, 300]);
$heap->insert([0, 10, 150]);
while (!
$heap->isEmpty()) {
[
$a, $b, $c] = $heap->extract();
echo
"a:$a, b:$b, c:$c\n";
}
?>

will output:

a:0, b:10
a:0, b:15
a:0, b:30
---
a:0, b:10, c:100
a:0, b:10, c:150
a:0, b:10, c:300
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