C++根据前序和中序构造二叉树

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

template<typename Type>
struct Node
{
    Type data;
    Node<Type> *left;
    Node<Type> *right;
    Node(Type d = Type()):data(d),left(NULL),right(NULL){}
};

template<typename Type>
class MTree
{
    public:
    MTree()
    {
        root = NULL;
    }
    void Init(const char *s1,const char *s2)
    {
        int n = strlen(s1);
        Init(root,s1,s2,n);
    }
    void Printf()
    {
        _Printf(root);
    }
    private:
    void _Printf(Node<Type> *t)
    {
        if(t!=NULL)
        {
            cout<<t->data<<"\t";
            _Printf(t->left);
            _Printf(t->right);
        }
    }
    void Init(Node<Type> *&t,const char *&s1,const char *s2,int n)
    {
    //根据二叉树的前序跟后续构造二叉树.
      int i = 0;
        if(*s1==‘\0‘)return;
        for(;i<=n;i++)
        {
            if(*s1==s2[i])
                {
                    break;
                }
        }
        if(i>n)return;
        t = new Node<Type>(*s1);
        Init(t->left,++s1,s2,i-1);
        Init(t->right,s1,s2+i+1,n-i);
    }
    Node<Type> *root;
};
int main()
{
    MTree<char> mt;
    char *s1 = new char[7];
    char *s2 = new char[7];
    strcpy(s1,"ABCDEFG");
    strcpy(s2,"CBDAFEG");
    mt.Init(s1,s2);
    mt.Printf();
    return 0;
}