If Google interview lets you write a tree traversal program in Python

A few days ago suddenly interested in Python, learned a few days also feel it is very concise and practical. Broke my so long time on Java C # C and VB aesthetic fatigue, let me a bright. "It's as simple as reading English," said the remark, which Python says is reasonable.

I am very fond of Python because I have heard that many Google programs are used in Python, and in Google App Engine and support Python. If you go to a Google interview or a written exam, it's likely that you'll get to the question: Using Python to implement tree traversal.

I tried to write a bit, but after all, is a rookie, there are questions please advise.

The results are as follows:

The source program is as follows:

#!user/bin/python

#树的实体 (including Id, value, Fatherid)

Class TreeModel:

"Tree View"

def __init__ (Self,id,value,fatherid):

Self. Id=id

Self.value=value

Self.fatherid=fatherid

Def show (self):

Return Self.value

# The traversal and display of the tree

Class Treeshow:

"Tree Show"

Loglist = [TreeModel (0, ' Addtree ', 0)] #记录已经遍历过的节点

Writtenlist = [TreeModel (0, ' Addtree ', 0)] #记录已经打印出的节点

def __init__ (self,rootid,list):

Self.rootid = Rootid

Self.list=list

#通过Id获取节点

def Getmodelbyid (Self,id):

For T in Self.list:

if t.id = = Id:

Return T

Return None

#判断是否有子节点

def havechild (self,t):

For T1 in Self.list:

if T1.fatherid = = T.id and not self. Isinloglist (T1):

Return True

Return False

#获取第一个没有遍历的子节点

def getfirstchild (self,t):

For T1 in Self.list:

if T1.fatherid = = T.id and not self. Isinloglist (T1):

return T1

Return None

#判断某节点是否已经被遍历

def isinloglist (self,t):

For T1 in Self.loglist:

if T1. Id = = T.id:

Return True

Return False

#判断某节点是否已经打印

def isinwrittenlist (self,t):

For T1 in Self.writtenlist:

if T1. Id = = T.id:

Return True

Return False

#获取父节点

def getfathertree (self,t):

For T1 in Self.list:

if T1. Id = = T.fatherid:

return T1

Return None

#遍历打印

Def show (self):

Currenttree = Self.getmodelbyid (Self.rootid)

s = '

Strnum = 1

while (True):

If Self.havechild (currenttree):

If not self. Isinwrittenlist (Currenttree):

Print S*strnum,currenttree.show ()

Self.writtenList.append (Currenttree)

Currenttree = Self.getfirstchild (currenttree)

Strnum + = 1

Continue

Else

if (currenttree.id = = Self.rootid):

Break

Else

If not self. Isinwrittenlist (Currenttree):

Print S*strnum,currenttree.show ()

Self.logList.append (Currenttree)

Currenttree = Self.getfathertree (currenttree)

Strnum-= 1

Continue

#初始化一些节点实例

T1 = TreeModel (1, ' A-1 ', 0)

T2 = TreeModel (2, ' B-1 ', 1)

T3 = TreeModel (3, ' B-2 ', 1)

T4 = TreeModel (4, ' C-1 ', 2)

T5 = TreeModel (5, ' C-2 ', 2)

T6 = TreeModel (6, ' C-3 ', 3)

T7 = TreeModel (7, ' C-4 ', 3)

T8 = TreeModel (8, ' D-1 ', 4)

T9 = TreeModel (9, ' E-1 ', 8)

T10 = TreeModel (Ten, ' E-2 ', 8)

#将这些节点实例链式存储起来 (as stored in a database)

List = [T1,t2,t3,t4,t5,t6,t7,t8,t9,t10]

#调用展示

ts = treeshow (1,list)

Ts.show ()

If Google interview lets you write a tree traversal program in Python