题目：输入两个二叉树A和B，判断B是不是A的子结构。

public boolean HasSubtree(Node Tree1,Node Tree2){        boolean result = false;        if(Tree1 != null && Tree2 != null){            if(Tree1.data == Tree2.data){                result = DoesTree1HaveTree2(Tree1,Tree2);            }            if(!result){                result = HasSubtree(Tree1.left,Tree2);            }            if(!result){                result = HasSubtree(Tree1.right,Tree2);            }        }    }        public boolean DoesTree1HaveTree2(Node Tree1,Node Tree2){        if(Tree1 == null){            return false;        }        if(Tree2 == null){            return true;        }        if(Tree1.data != Tree2.data){            return false;        }        return DoesTree1HaveTree2(Tree1.left,Tree2,left) && DoesTree1HaveTree2(Tree1.right,Tree2.right);    }