dojo_app/js/library/dojox/collections/BinaryTree.js

define(["dojo/_base/kernel", "dojo/_base/array", "./_base"], function(dojo, darray, dxc){

	dxc.BinaryTree=function(data){
		function node(data, rnode, lnode){
			this.value=data||null;
			this.right=rnode||null;
			this.left=lnode||null;
			this.clone=function(){
				var c=new node();
				if(this.value.value){
					c.value=this.value.clone();
				}else{
					c.value=this.value;
				}
				if(this.left!=null){
					c.left=this.left.clone();
				}
				if(this.right!=null){
					c.right=this.right.clone();
				}
				return c;
			}
			this.compare=function(n){
				if(this.value>n.value){ return 1; }
				if(this.value<n.value){ return -1; }
				return 0;
			}
			this.compareData=function(d){
				if(this.value>d){ return 1; }
				if(this.value<d){ return -1; }
				return 0;
			}
		}

		function inorderTraversalBuildup(current, a){
			if(current){
				inorderTraversalBuildup(current.left, a);
				a.push(current.value);
				inorderTraversalBuildup(current.right, a);
			}
		}

		function preorderTraversal(current, sep){
			var s="";
			if (current){
				s=current.value.toString() + sep;
				s+=preorderTraversal(current.left, sep);
				s+=preorderTraversal(current.right, sep);
			}
			return s;
		}
		function inorderTraversal(current, sep){
			var s="";
			if (current){
				s=inorderTraversal(current.left, sep);
				s+=current.value.toString() + sep;
				s+=inorderTraversal(current.right, sep);
			}
			return s;
		}
		function postorderTraversal(current, sep){
			var s="";
			if (current){
				s=postorderTraversal(current.left, sep);
				s+=postorderTraversal(current.right, sep);
				s+=current.value.toString() + sep;
			}
			return s;
		}
		
		function searchHelper(current, data){
			if(!current){ return null; }
			var i=current.compareData(data);
			if(i==0){ return current; }
			if(i>0){ return searchHelper(current.left, data); }
			else{ return searchHelper(current.right, data); }
		}

		this.add=function(data){
			var n=new node(data);
			var i;
			var current=root;
			var parent=null;
			while(current){
				i=current.compare(n);
				if(i==0){ return; }
				parent=current;
				if(i>0){ current=current.left; }
				else{ current=current.right; }
			}
			this.count++;
			if(!parent){
				root=n;
			}else{
				i=parent.compare(n);
				if(i>0){
					parent.left=n;
				}else{
					parent.right=n;
				}
			}
		};
		this.clear=function(){
			root=null;
			this.count=0;
		};
		this.clone=function(){
			var c=new dxc.BinaryTree();
			var itr=this.getIterator();
			while(!itr.atEnd()){
				c.add(itr.get());
			}
			return c;
		};
		this.contains=function(data){
			return this.search(data) != null;
		};
		this.deleteData=function(data){
			var current=root;
			var parent=null;
			var i=current.compareData(data);
			while(i!=0&&current!=null){
				if(i>0){
					parent=current;
					current=current.left;
				}else if(i<0){
					parent=current;
					current=current.right;
				}
				i=current.compareData(data);
			}
			if(!current){ return; }
			this.count--;
			if(!current.right){
				if(!parent){
					root=current.left;
				}else{
					i=parent.compare(current);
					if(i>0){ parent.left=current.left; }
					else if(i<0){ parent.right=current.left; }
				}
			}
			else if(!current.right.left){
				if(!parent){
					root=current.right;
				}else{
					i=parent.compare(current);
					if(i>0){ parent.left=current.right; }
					else if(i<0){ parent.right=current.right; }
				}
			}
			else{
				var leftmost=current.right.left;
				var lmParent=current.right;
				while(leftmost.left!=null){
					lmParent=leftmost;
					leftmost=leftmost.left;
				}
				lmParent.left=leftmost.right;
				leftmost.left=current.left;
				leftmost.right=current.right;
				if(!parent){
					root=leftmost;
				}else{
					i=parent.compare(current);
					if(i>0){ parent.left=leftmost; }
					else if(i<0){ parent.right=leftmost; }
				}
			}
		};
		this.getIterator=function(){
			var a=[];
			inorderTraversalBuildup(root, a);
			return new dxc.Iterator(a);
		};
		this.search=function(data){
			return searchHelper(root, data);
		};
		this.toString=function(order, sep){
			if(!order){ order=dxc.BinaryTree.TraversalMethods.Inorder; }
			if(!sep){ sep=","; }
			var s="";
			switch(order){
				case dxc.BinaryTree.TraversalMethods.Preorder:
					s=preorderTraversal(root, sep);
					break;
				case dxc.BinaryTree.TraversalMethods.Inorder:
					s=inorderTraversal(root, sep);
					break;
				case dxc.BinaryTree.TraversalMethods.Postorder:
					s=postorderTraversal(root, sep);
					break;
			};
			if(s.length==0){ return ""; }
			else{ return s.substring(0, s.length - sep.length); }
		};

		this.count=0;
		var root=this.root=null;
		if(data){
			this.add(data);
		}
	}
	dxc.BinaryTree.TraversalMethods={
		Preorder: 1, Inorder: 2, Postorder: 3
	};
	return dxc.BinaryTree;
});