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POGeneral tree traversal(infinite) in breadth-first search manner
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16340374
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2013-05-02T14:12:48.987
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2013-05-02T14:23:00.023
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ViewCount
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Body
I have a Tree Structure where each node has 5 child nodes and more than that are not allowed. I wish to traverse this tree in breadth-first search manner. <img src="https://i.stack.imgur.com/KdMjj.png" alt="enter image description here"> Now I wish to calculate empty node from selected parent using breadth-first search manner. e.g. <ol> <li>if given parent is 1, then function must return node 4 because it has positions available. </li> <li>If given parent is 2, then it must return node 7</li> </ol> I am using PHP(codeigniter) + Mysql for this. My controler <pre><code>public function addmember() { $current_node = $this->input->post('member'); $empty_location = $this->tree_model->GetEmptyPositions($current_node); if($empty_location != 0) { echo "Position available"; } else { $next_nodes = $this->tree_model->GetAllChilds($current_node); $i=0; for($i=0;$i<5;$i++){ $result = $this->tree_model->GetEmptyPositions($next_nodes[$i]); if($result != 0 ) { $current_node = $next_nodes[$i]; goto exe; } } } exe: echo $current_node; } </code></pre> and my model <pre><code>//get number of empty nodes of current member public function GetEmptyPositions($id) { $this->db->select('empty_position'); $this->db->from('member'); $this->db->where('member_id',$id); $result = $this->db->get(); if ($result->num_rows() > 0) foreach($result->result() as $empty_pos) return $empty_pos->empty_position; } //get all childs of current node public function GetAllChilds($id) { $this->db->select('member_id'); $this->db->from('member'); $this->db->where('tree_parent_id',$id); $result = $this->db->get(); if ($result->num_rows() > 0) { $i = 0; foreach($result->result_array() as $member_id) { $member_array[$i] = $member_id['member_id']; $i++; } return $member_array; } } </code></pre> Database <pre><code>CREATE TABLE IF NOT EXISTS `member` ( `member_id` int(11) NOT NULL AUTO_INCREMENT, `datetime` datetime DEFAULT NULL, `parent_id` int(11) DEFAULT NULL, `tree_parent_id` int(11) DEFAULT NULL, `empty_position` tinyint(4) DEFAULT '5', // stores how many empty positions remain if zero move to next node `name` varchar(20) COLLATE utf8_unicode_ci DEFAULT NULL, PRIMARY KEY (`member_id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci; </code></pre> Where I stuck up! I am able to traverse till node 6 by above code. but in next iteration i have need to check @ node 7 since nodes will be in order 5 rase to n and it is not finite tree structure. next tree traversal order 7 8 9 10 11 12 13 14 16 ......
Tags
<php><mysql><codeigniter><tree>
Title
General tree traversal(infinite) in breadth-first search manner
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