先序遍历非递归算法 #define maxsize 100 typedef struct { Bitree Elem[maxsize] int top }SqStack void PreOrderUnrec(Bitree t) { SqStack s StackInit(s) p=t while (p!=null !StackEmpty(s-preorder non - recursive algorithm # define maxsize 100 typedef struct (Bitree Elem [maxsize]) int top SqStack void PreOrderUnrec (Bitree t) (SqStack s StackInit (s) p = t while (p! = Null! StackEmpty (s