python-哈夫曼树

 #!/usr/bin/python
#coding=utf-8
#哈夫曼树创建

class Node():
    def __init__(self,value,left=None,right=None):
        self.value=value
        self.left=left
        self.right=right
class Halfman():
    def init(self,k):
        k.sort()
       # key=Node(k[0])
        self.root=Node(k[0])
        if len(k)==len(set(k)):  #无重复项判定
            for i in range(1,len(k)):
                node=Node(k[i])
                if i==1: 
                    max=k[i]*(len(k)-i)+self.root.value*(len(k)-1)
                else:
                    max=k[i]*(len(k)-i)+self.root.value
                root=Node(max,self.root,node)
                self.root=root
            return self.root
    def pre(self,root):
        if root==None:return
        print root.value
        self.pre(root.left)
        self.pre(root.right)

k=[2,8,5,6,4,7,9,1,3]
tree=Halfman()
a=tree.init([2,8,5,6,4,7,9,1,3])

tree.pre(a)

print '*'*40

print a.value
print a.left.value
print a.right.value