4-10：二叉树镜像

问题：二叉树镜像

输入二叉树，求二叉树的镜像。

void reversetree(TreeNode* tree)
{
	if (tree == NULL)
		return;
	TreeNode* treeleft = tree->getleft();
	TreeNode* treeright = tree->getright();
	if (treeleft != NULL)
	{
		tree->setright(treeleft);
		reversetree(treeleft);
	}
	if (treeright != NULL)
	{
		tree->setleft(treeright);
		reversetree(treeright);
	}

}