树-NO.6 求叶子节点到根节点的路径 增加一个parent指针

struct TreeNode{
    int val ;
    TreeNode *parent;
    TreeNode*left,
    TreeNode*right;
}

void create (TreeNode*root, TreeNode*pre)
{
    if(root)
   {
       root->parent= pre;
       pre=root;

       create(root-left);
       create(root->right);
   }
}

int main()
{

}