迪科斯彻算法（Dijkstra）

<?php
class Dijkstra
{
private $G;
public function __construct()
{
//有向图存储
$this->G = array(
array(0,1,2,0,0,0,0),
array(0,0,0,1,2,0,0),
array(0,0,0,0,0,2,0),
array(0,0,0,0,0,1,3),
array(0,0,0,0,0,0,3),
array(0,0,0,0,0,0,1),
array(0,0,0,0,0,0,0),
);
}
public function calculate()
{
// 存储已经选择节点和剩余节点
$U = array(0);
$V = array(1,2,3,4,5,6);
// 存储路径上节点距离源点的最小距离
$d = array();
//初始化图中节点与源点0的最小距离
for($i=1;$i<7;$i++)
{
if($this->G[0][$i]>0)
{
$d[$i] = $this->G[0][$i];
}
else
{
$d[$i] = 1000000;
}
}
// n-1次循环完成转移节点任务
for($l=0;$l<6;$l++)
{
// 查找剩余节点中距离源点最近的节点v
$current_min = 100000;
$current_min_v = 0;
foreach($V as $k=>$v)
{
if($d[$v] < $current_min)
{
$current_min = $d[$v];
$current_min_v = $v;
}
}
//从V中更新顶点到U中
array_push($U,$current_min_v);
array_splice($V,array_search($current_min_v,$V),1);
//更新
foreach($V as $k=>$u)
{
if($this->G[$current_min_v][$u]!=0&&$d[$u]>$d[$current_min_v]+$this->G[$current_min_v][$u])
{
$d[$u] = $d[$current_min_v]+$this->G[$current_min_v][$u];
}
}
}
foreach($d as $k => $u)
{
echo $k.'=>'.$u.'<br>';
}
}
}
?>