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);
			}
		}
	}
?>