中先后遍历的递归

/*二叉树的建立shudefeidigui及先序、中序、后序遍历的递归*/ #define NULL 0 #include typedef struct bitnode {char data; struct bitnode *lchild,*rchild; }bitnode,*bitree; void creatree(bitree *t) { char ch; scanf("%c",&ch); if(ch=='.')*t=NULL; else {*t=(bitree)malloc(sizeof(bitnode)); (*t)->data