树的节点存储的是学生的信息

节点的比较以信息中的学号为准；

<?php
    class Node{
        private $num;//学生学号
        private $name;//学生姓名
        private $scoreChinese;//学生语文成绩
        private $scoreMath;//数学成绩
        private $scoreEnglish;//英语成绩
        private $left;
        private $right;
        
        public function __construct(){
            $this->left  = null;
            $this->right = null;
        }
        public function __set($key,$value){
                $this->$key = $value;
        }
        public function __get($key){
            if(isset($this->$key)){
                return $this->$key;
            }
        }
    }
    class Tree{
        private $top;//树顶节点
        
        public function __construct($array){
            //生成树
            $falses = $this->makeTree($array);
            $this->readTree();
        }
        
        public function makeTree($array){
            if(empty($array)){
                $this->top = null;
                return;
            }
            //选择树顶节点
            $temp = $array[floor(count($array)/2)];
            $this->top->num 			= $temp['num'];
            $this->top->name 			= $temp['name'];
            $this->top->scoreChinese	= $temp['scoreChinese'];
            $this->top->scoreMath 		= $temp['scoreMath'];
            $this->top->scoreEnglish	= $temp['scoreEnglish'];
            $this->top->left 			= null;
            $this->top->right 			= null;
            
            unset($array[floor(count($array)/2)]);
            
            $false  = 0;//建树失败的节点
            foreach($array as $value){
                if(false == $this->insert($value)){
                    $false++;
                }
            }
        }
        /**
            插入节点
        */
        public function insert($info){
            $aNode = new Node();
            $aNode->num  	 	 = $info['num'];
            $aNode->name 		 = $info['name'];
            $aNode->scoreChinese = $info['scoreChinese'];
            $aNode->scoreMath  	 = $info['scoreMath'];
            $aNode->scoreEnglish = $info['scoreEnglish'];
            $aNode->left 		 = null;
            $aNode->right 		 = null;
            
            if(null == $this->top){
                $this->top = $aNode;
                return;
            }
            $nowNode = $this->top;
            while(true){
                if($nowNode->num == $aNode->num){
                    return false;
                }elseif($nowNode->num>$aNode->num && null == $nowNode->left){
                    $nowNode->left = $aNode;
                    return true;
                }elseif($nowNode->num<$aNode->num && null == $nowNode->right){
                    $nowNode->right = $aNode;
                    return true;
                }elseif($nowNode->num>$aNode->num && $nowNode->left != null){
                    $nowNode = $nowNode->left;
                }elseif($nowNode->num<$aNode->num && $nowNode->right != null){
                    $nowNode = $nowNode->right;
                }
            }
        }
        
        /**
            查询节点
        */
        public function search($num){
            $nowNode = $this->top;
            while(true){
                if($nowNode->num == $num){
                    return $nowNode;
                }elseif($nowNode->num>$num && null == $nowNode->left){
                    return null;
                }elseif($nowNode->num<$num && null == $nowNode->right){
                    return null;
                }elseif($nowNode->num>$num && $nowNode->left!=null){
                    $nowNode = $nowNode->left;
                }elseif($nowNode->num<$num && $nowNode->right!=null){
                    $nowNode = $nowNode->right;
                }
            }
        }
        /**
            树是否为空
        */
        public function isEmpty(){
            if(is_null($this->top)){
                return true;
            }else{
                return false;
            }
        }
        /**
            中序便利树
        */
        public function readTree(){
            $result = array();
            $this->read($this->top,$result);
            return $result;
        }
        
        private function read($nowNode,&$result){
            if(null != $nowNode->left){
                $this->read($nowNode->left,$result);
            }
            
            array_push($result,$nowNode);
            if(null != $nowNode->right){
                $this->read($nowNode->right,$result);
            }
        }
    }
?>