编写一个程序exp5-3.cpp, 根据给定的先序序列ABDEHJKLMNCFGI和中序序列DBJHLKMNEAFCGI构建相应的二叉树, 并输出构建好的二叉树.

    #include "btree.cpp"
    BTNode *CreateBT1(char *pre,char *in,int n)
    	                
    
    {      BTNode *s;  char *p;  int k;              
       if (n<=0) return NULL;	
       s=(BTNode *)malloc(sizeof(BTNode));         
       s->data=*pre;			
       for (p=in;p<in+n;p++)	   
    	 if (*p==*pre)			
     	      break;		
       k=p-in; 			
       s->lchild=CreateBT1(pre+1,in,k);	              
       s->rchild=CreateBT1(pre+k+1,p+1,n-k-1);  
       return s;
    } 
    main()
    {
    	BTNode *s;
    s=CreateBT1("ABDEHJKLMNCFGI","DBJ