我有一个称为make-leaf-set的过程,该过程创建叶节点和另一个过程,该过程将最低的first-high排序。将虚线对合并到huffman树中
(define (make-leaf-set pairs)
(if (null? pairs)
'()
(let ((pair (car pairs)))
(adjoin-set (make-leaf (car pair)
(cdr pair))
(make-leaf-set (cdr pairs))))))
(define (adjoin-set x set)
(cond ((null? set) (list x))
((< (weight x) (weight (car set))) (cons x set))
(else (cons (car set)
(adjoin-set x (cdr set))))))
"Predefined dotted paires"
(define pairs '((a . 2) (b . 5) (c . 1) (d . 3) (e . 1) (f . 3)))
=> ((leaf e 1) (leaf c 1) (leaf a 2) (leaf f 3) (leaf d 3) (leaf b 5))
对在使用时可以很好地工作(制作叶组对)。一切都是排序的。 我也用这就叫make码树
(define (make-code-tree left right)
(list left
right
(append (symbols left) (symbols right))
(+ (weight left) (weight right))))
(define (symbols tree)
(if (leaf? tree)
(list (symbol-leaf tree))
(caddr tree)))
(define (weight tree)
(if (leaf? tree)
(weight-leaf tree)
(cadddr tree)))
- 的目标是创造这需要对列表,然后创建一个哈夫曼树的过程另一个程序。
作为开始我COMED了这个
(define (grow-huffman-tree list)
(successive-merge (make-leaf-set list) '()))
(define (successive-merge par tree)
(if (null? par)
tree
(append (make-code-tree (car par) (cadr par)) tree)))
因为它位于它合并两个第一元件和给出((叶ë1)(叶的C 1)(EC)2) 。 但我希望它合并所有树叶,使它像huffman-tree一样构建,并且我无法设法将其他树叶合并到此树中。我试图调用(连续合并(cdr par)树)将导致元素d 3上的错误...
我不认为你已经正确地吸收意见来自:http://stackoverflow.com/questions/15350954/get-pairs-out-of-a-huffman-tree/;你从'make-code-tree'返回的数据类的数据定义在哪里? (就此而言,你的'leaf?'过程在哪里定义? – pnkfelix 2013-03-13 02:30:55