Detailed explanation of depth-first search algorithm implemented in PHP

This article mainly introduces the implementation of depth-first search algorithm (DFS, Depth First Search) in PHP. It briefly analyzes the principle of depth-first search algorithm and combines specific examples to give the specific steps and related operations of PHP to implement depth-first search. For tips, friends who need them can refer to

. This article describes the implementation of depth-first search algorithm in PHP. Share it with everyone for your reference, the details are as follows:

Implementation principle of depth-first search:

Implementation code:

dfs_save = array( array(0,1,1,1,0,0,0,0,0), array(1,0,0,0,1,0,0,0,0), array(1,0,0,0,0,1,0,0,0), array(1,0,0,0,0,0,1,0,0), array(0,1,0,0,0,1,0,0,1), array(0,0,1,0,1,0,0,1,0), array(0,0,0,1,0,0,0,0,0), array(0,0,0,0,0,1,0,0,0), array(0,0,0,0,1,0,0,0,0), ); $this->arr = array(); } //深度优先搜索的递归实现方法 public function dfs($v) { //对顶点做一些操作 echo str_repeat("-",$this->k); echo 'V'.($v+1).'
'; //记录已访问的顶点 $this->arr[]= $v; //查找与顶点相连接的顶点，如果存在就继续深度优先搜索 for($i=0;$i<9;$i++) { if(!in_array($i,$this->arr)&&$this->dfs_save[$v][$i]==1) { $this->k++; $this->dfs($i); } } $this->k--; return; } } ?>

Achieve output results:

V1 -V2 --V5 ---V6 ----V3 ----V8 ---V9 -V4 --V7

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