C++求二叉树的最大高度差

#include <iostream>
#include <string.h>
using namespace std;

template<typename Type>
struct Node
{
    Type data;
    Node *left;
    Node  *right;
    Node(Type d = Type()):data(d),left(NULL),right(NULL){}
    //vs2013太变态了，一个空格出现未知文件尾出错，我找了10分钟。
};

template<typename Type>
class Tree
{
public:
    Tree()
    {
        root = NULL;
        flags = '#';
    }
    void Insert(const char *str)
    {
        Insert(root, str);
    }
    void Printf()
    {
        Printf(root);
    }
    int GetLength()//求最大高度差。
    {
        int i = GetLengthMax();
        int j  = GetLengthMin();
        return i - j;
    }
    int GetLengthMax()
    {
        return GetLengthMax(root);
    }
    int GetLengthMin()
    {
        return GetLengthMin(root);
    }
private:
    int GetLengthMax(Node<Type> *t)
    {
        if (t == NULL)
            return 0;
        else
        {
            return GetLengthMax(t->left)>GetLengthMax(t->right)?GetLengthMax(t->left)+1:GetLengthMax(t->right) + 1;
        }
    }
    int GetLengthMin(Node<Type>* t)
    {
        if (t == NULL)
            return 0;
        else
        {
            return GetLengthMin(t->left)<GetLengthMin(t->right) ? GetLengthMin(t->left) + 1 : GetLengthMin(t->right) + 1;
        }
    }
    void Printf(Node<Type> *t)
    {
        if (t != NULL)
        {
            cout << t->data << "  ";
            Printf(t->left);
            Printf(t->right);
        }
    }
    void Insert(Node<Type> *&t, const char*& s)
    {
        if (*s == flags)
        {
            t = NULL;
            return;
        }
        else
        {
            t = new Node<Type>(*s);
            Insert(t->left,++s);
            Insert(t->right,++s);
        }
    }
private:
    Node<Type> *root;
    char flags;
};

int main()
{
    Tree<char> t;
    char *s = new char[20];//1234####56##7
    strcpy(s,"1##");
    t.Insert(s);
    t.Printf();
    cout << endl;
    cout << t.GetLength()<< endl;
    return 0;
}