Binary tree mid-order traversal sequence

Design algorithm to find the mid-order traversal sequence of binary tree.

[Input form] A line of character string. This line is the pre-order traversal sequence of the extended binary tree, which is used to construct the binary tree.
[Output form] Mid-order traversal sequence in binary tree.
[Sample input] AB # D ## C ##
[Sample output]
BDAC
analysis:
1. First build a binary tree and nodes
2. Use recursion to perform in-order traversal
3. Print output

struct BiNode//节点
{
    DataType data;
    BiNode<DataType>*lchild,*rchild;
};

template<typename DataType>//二叉树
class BiTree
{
public:
    BiTree()
    {
        root=Create();
    }
    void InOrder()
    {
        InOrder(root);
    }
private:
    BiNode<DataType>*Create();
    void InOrder(BiNode<DataType>*bt);
    BiNode<DataType>*root;

};

Construct a binary tree

template<typename DataType>
BiNode<DataType>*BiTree<DataType>::Create()
{
    BiNode<DataType>*bt;
    char ch;
    cin>>ch;
    if(ch=='#')
        bt=NULL;
    else
    {
        bt=new BiNode<DataType>;
        bt->data=ch;
        bt->lchild=Create();
        bt->rchild=Create();
    }
    return bt;
}

Output function

template<typename DataType>
void BiTree<DataType>::InOrder(BiNode<DataType>*bt)
{
    if(bt==NULL)
        return;
    else
    {
        InOrder(bt->lchild);
        cout<<bt->data;
        InOrder(bt->rchild);
    }
}

main function

int main()
{
    BiTree<char>t1;//对应自己写的类
    t1.InOrder();//对应自己写的输出函数
}