请问这个使用广义表非递归构造二叉树还有什么可以增进的地方？

[dthgmf]

	public static BinaryTree<String> createTree(String str) {
		int j = 1;
		BinaryNode<String> p = null;
		BinaryNode<String> q = null;
		BinaryTree<String> tree = new BinaryTree<String>();
		tree.root = new BinaryNode<String>(str.charAt(0) + "");
		p = tree.root;
		LinkedStack<BinaryNode<String>> stack = new LinkedStack<BinaryNode<String>>(); 
		stack.push(p);
		System.out.println(str.length());
		while(j < str.length()) {
			char ch = str.charAt(j);
			if(ch == '(') {
				q = stack.get();
				if((str.charAt(j+1) != '^')) {
					q.left = new BinaryNode<String>(str.charAt(j+1)+"");
					q = q.left;
					stack.push(q);
					j=j+2;
				} else {
					stack.push(q);
					j=j+2;
				}
			}
			if(ch == ',') {
				if((str.charAt(j+1) != '^')) {
					stack.pop();
					q = stack.get();
					q.right = new BinaryNode<String>(str.charAt(j+1)+"");
					q = q.right;
					stack.push(q);
					j=j+2;
				} else {
					q = stack.get();
					j=j+2;
				}
			}
			if(ch == ')') {
				stack.pop();
				j++;
			}
		}
		tree.root = p;
		return tree;
	}

get()是返回栈顶，pop()是出栈，请问各位大神，还有什么需要简化的地方？