Ch05 Lab - 원형/이중 연결 리스트

📘 교재 예제 (Code)

📘 Textbook Examples (Code)

Code05-01.py

원형 연결 리스트의 노드를 생성합니다

class Node() :
	def __init__ (self) :
		self.data = None
		self.link = None

node1 = Node()
node1.data = "다현"
node1.link = node1

node2 = Node()
node2.data = "정연"
node1.link = node2
node2.link = node1

node3 = Node()
node3.data = "쯔위"
node2.link = node3
node3.link = node1

node4 = Node()
node4.data = "사나"
node3.link = node4
node4.link = node1

node5 = Node()
node5.data = "지효"
node4.link = node5
node5.link = node1

current = node1
print(current.data, end =' ')
while current.link != node1 :
	current = current.link
	print(current.data, end=' ')

Code05-01.py

Creates nodes for a circular linked list

class Node() :
	def __init__ (self) :
		self.data = None
		self.link = None

node1 = Node()
node1.data = "Dahyun"
node1.link = node1

node2 = Node()
node2.data = "Jungyeon"
node1.link = node2
node2.link = node1

node3 = Node()
node3.data = "Tzuyu"
node2.link = node3
node3.link = node1

node4 = Node()
node4.data = "Sana"
node3.link = node4
node4.link = node1

node5 = Node()
node5.data = "Jihyo"
node4.link = node5
node5.link = node1

current = node1
print(current.data, end =' ')
while current.link != node1 :
	current = current.link
	print(current.data, end=' ')

Code05-02.py

원형 연결 리스트에서 노드를 삽입합니다

class Node() :
	def __init__ (self) :
		self.data = None
		self.link = None

node1 = Node()
node1.data = "다현"
node1.link = node1

node2 = Node()
node2.data = "정연"
node1.link = node2
node2.link = node1

node3 = Node()
node3.data = "쯔위"
node2.link = node3
node3.link = node1

node4 = Node()
node4.data = "사나"
node3.link = node4
node4.link = node1

node5 = Node()
node5.data = "지효"
node4.link = node5
node5.link = node1

newNode = Node()
newNode.data = "재남"
newNode.link = node2.link   # 정연 노드의 링크
node2.link = newNode

current = node1
print(current.data, end = ' ')
while current.link != node1 :
	current = current.link
	print(current.data, end = ' ')

Code05-02.py

Inserts nodes into a circular linked list

class Node() :
	def __init__ (self) :
		self.data = None
		self.link = None

node1 = Node()
node1.data = "Dahyun"
node1.link = node1

node2 = Node()
node2.data = "Jungyeon"
node1.link = node2
node2.link = node1

node3 = Node()
node3.data = "Tzuyu"
node2.link = node3
node3.link = node1

node4 = Node()
node4.data = "Sana"
node3.link = node4
node4.link = node1

node5 = Node()
node5.data = "Jihyo"
node4.link = node5
node5.link = node1

newNode = Node()
newNode.data = "Jaenam"
newNode.link = node2.link   # Jungyeon node's link
node2.link = newNode

current = node1
print(current.data, end = ' ')
while current.link != node1 :
	current = current.link
	print(current.data, end = ' ')

Code05-03.py

원형 연결 리스트에서 노드를 삭제합니다

class Node() :
	def __init__ (self) :
		self.data = None
		self.link = None

node1 = Node()
node1.data = "다현"
node1.link = node1

node2 = Node()
node2.data = "정연"
node1.link = node2
node2.link = node1

node3 = Node()
node3.data = "쯔위"
node2.link = node3
node3.link = node1

node4 = Node()
node4.data = "사나"
node3.link = node4
node4.link = node1

node5 = Node()
node5.data = "지효"
node4.link = node5
node5.link = node1

node2.link = node3.link
del(node3)

current = node1
print(current.data, end = ' ')
while current.link != node1 :
	current = current.link
	print(current.data, end = ' ')

Code05-03.py

Deletes nodes from a circular linked list

class Node() :
	def __init__ (self) :
		self.data = None
		self.link = None

node1 = Node()
node1.data = "Dahyun"
node1.link = node1

node2 = Node()
node2.data = "Jungyeon"
node1.link = node2
node2.link = node1

node3 = Node()
node3.data = "Tzuyu"
node2.link = node3
node3.link = node1

node4 = Node()
node4.data = "Sana"
node3.link = node4
node4.link = node1

node5 = Node()
node5.data = "Jihyo"
node4.link = node5
node5.link = node1

node2.link = node3.link
del(node3)

current = node1
print(current.data, end = ' ')
while current.link != node1 :
	current = current.link
	print(current.data, end = ' ')

Code05-04.py

원형 연결 리스트의 삽입/삭제 통합 프로그램입니다

## 클래스와 함수 선언 부분 ##
class Node() :
	def __init__ (self) :
		self.data = None
		self.link = None

def printNodes(start) :

	current = start
	if current.link == None :
		return
	print(current.data, end = ' ')
	while current.link != start:
		current = current.link
		print(current.data, end = ' ')
	print()

## 전역 변수 선언 부분 ##
memory = []
head, current, pre = None, None, None
dataArray = ["다현", "정연", "쯔위", "사나", "지효"]

## 메인 코드 부분 ##

if __name__ == "__main__" :

	node = Node()		
	node.data = dataArray[0]	# 첫 번째 노드
	head = node
	node.link = head
	memory.append(node)

	for data in dataArray[1:] :	# 두 번째 이후 노드
		pre = node
		node = Node()
		node.data = data
		pre.link = node
		node.link = head
		memory.append(node)

	printNodes(head)

Code05-04.py

Complete circular linked list with insert and delete

## Class & Function Declarations ##
class Node() :
	def __init__ (self) :
		self.data = None
		self.link = None

def printNodes(start) :

	current = start
	if current.link == None :
		return
	print(current.data, end = ' ')
	while current.link != start:
		current = current.link
		print(current.data, end = ' ')
	print()

## Global Variables ##
memory = []
head, current, pre = None, None, None
dataArray = ["Dahyun", "Jungyeon", "Tzuyu", "Sana", "Jihyo"]

## Main Code ##
if __name__ == "__main__" :

	node = Node()		
	node.data = dataArray[0]	# First node
	head = node
	node.link = head
	memory.append(node)

	for data in dataArray[1:] :	# From the second node onward
		pre = node
		node = Node()
		node.data = data
		pre.link = node
		node.link = head
		memory.append(node)

	printNodes(head)

Code05-05.py

이중 연결 리스트의 노드를 생성하고 연결합니다

## 클래스와 함수 선언 부분 ##
class Node() :
    def __init__ (self) :
        self.data = None
        self.link = None

def printNodes(start):

	current = start
	if current.link == None :
		return
	print(current.data, end=' ')
	while current.link != start:
		current = current.link
		print(current.data, end=' ')
	print()

def insertNode(findData, insertData) :

	global memory, head, current, pre

	if head.data == findData :		# 첫 번째 노드 삽입
		node = Node()
		node.data = insertData
		node.link = head
		last = head		# 마지막 노드를 첫 번째 노드로 우선 지정
		while last.link != head :	# 마지막 노드를 찾으면 반복 종료
			last = last.link	# last를 다음 노드로 변경
		last.link = node		# 마지막 노드의 링크에 새 노드 지정
		head = node
		return

	current = head
	while current.link != head :		# 중간 노드 삽입
		pre = current
		current = current.link
		if current.data == findData :
			node = Node()
			node.data = insertData
			node.link = current
			pre.link = node
			return

	node = Node()			 # 마지막 노드 삽입
	node.data = insertData
	current.link = node
	node.link = head

## 전역 변수 선언 부분 ##
memory = []
head, current, pre = None, None, None
dataArray = ["다현", "정연", "쯔위", "사나", "지효"]

## 메인 코드 부분 ##

if __name__ == "__main__" :

	node = Node()
	node.data = dataArray[0]	# 첫 번째 노드
	head = node
	node.link = head
	memory.append(node)

	for data in dataArray[1:] :	# 두 번째 이후 노드
		pre = node
		node = Node()
		node.data = data
		pre.link = node
		node.link = head
		memory.append(node)

	printNodes(head)

	insertNode("다현", "화사")
	printNodes(head)

	insertNode("사나", "솔라")
	printNodes(head)

	insertNode("재남", "문별")
	printNodes(head)

Code05-05.py

Creates and connects nodes of a doubly linked list

## Class & Function Declarations ##
class Node() :
    def __init__ (self) :
        self.data = None
        self.link = None

def printNodes(start):

	current = start
	if current.link == None :
		return
	print(current.data, end=' ')
	while current.link != start:
		current = current.link
		print(current.data, end=' ')
	print()

def insertNode(findData, insertData) :

	global memory, head, current, pre

	if head.data == findData :		# Insert before the first node
		node = Node()
		node.data = insertData
		node.link = head
		last = head		# Set last node as first node initially
		while last.link != head :	# Stop loop when last node is found
			last = last.link	# Change last to next node
		last.link = node		# Set last node's link to new node
		head = node
		return

	current = head
	while current.link != head :		# Insert in the middle
		pre = current
		current = current.link
		if current.data == findData :
			node = Node()
			node.data = insertData
			node.link = current
			pre.link = node
			return

	node = Node()			 # Insert at the end
	node.data = insertData
	current.link = node
	node.link = head

## Global Variables ##
memory = []
head, current, pre = None, None, None
dataArray = ["Dahyun", "Jungyeon", "Tzuyu", "Sana", "Jihyo"]

## Main Code ##
if __name__ == "__main__" :

	node = Node()
	node.data = dataArray[0]	# First node
	head = node
	node.link = head
	memory.append(node)

	for data in dataArray[1:] :	# From the second node onward
		pre = node
		node = Node()
		node.data = data
		pre.link = node
		node.link = head
		memory.append(node)

	printNodes(head)

	insertNode("Dahyun", "Hwasa")
	printNodes(head)

	insertNode("Sana", "Solar")
	printNodes(head)

	insertNode("Jaenam", "Moonbyul")
	printNodes(head)

Code05-06.py

이중 연결 리스트에 노드를 삽입합니다

## 클래스와 함수 선언 부분 ##
class Node() :
	def __init__ (self) :
		self.data = None
		self.link = None

def printNodes(start):

	current = start
	if current.link == None :
		return
	print(current.data, end=' ')
	while current.link != start:
		current = current.link
		print(current.data, end=' ')
	print()

def deleteNode(deleteData) :

	global memory, head, current, pre

	if head.data == deleteData :		# 첫 번째 노드 삭제
		current = head
		head = head.link
		last = head
		while last.link != current:		# 마지막 노드를 찾으면 반복 종료
			last = last.link		# last를 다음 노드로 변경
		last.link = head			# 마지막 노드의 링크에 head가 가리키는 노드 지정
		del(current)
		return

	current = head	                        	# 첫 번째 외 노드 삭제
	while current.link != head :
		pre = current
		current = current.link
		if current.data == deleteData :  	# 중간 노드를 찾았을 때
			pre.link = current.link
			del(current)
			return

## 전역 변수 선언 부분 ##
memory = []
head, current, pre = None, None, None
dataArray = ["다현", "정연", "쯔위", "사나", "지효"]

## 메인 코드 부분 ##

if __name__ == "__main__" :

	node = Node()		# 첫 번째 노드
	node.data = dataArray[0]
	head = node
	node.link = head
	memory.append(node)

	for data in dataArray[1:] :	# 두 번째 이후 노드
		pre = node
		node = Node()
		node.data = data
		pre.link = node
		node.link = head
		memory.append(node)

	printNodes(head)

	deleteNode("다현")
	printNodes(head)

	deleteNode("쯔위")
	printNodes(head)

	deleteNode("지효")
	printNodes(head)

	deleteNode("재남")
	printNodes(head)

Code05-06.py

Inserts nodes into a doubly linked list

## Class & Function Declarations ##
class Node() :
	def __init__ (self) :
		self.data = None
		self.link = None

def printNodes(start):

	current = start
	if current.link == None :
		return
	print(current.data, end=' ')
	while current.link != start:
		current = current.link
		print(current.data, end=' ')
	print()

def deleteNode(deleteData) :

	global memory, head, current, pre

	if head.data == deleteData :		# Delete the first node
		current = head
		head = head.link
		last = head
		while last.link != current:		# Stop loop when last node is found
			last = last.link		# Change last to next node
		last.link = head			# Set last node's link to the node head points to
		del(current)
		return

	current = head	                        	# Delete a non-first node
	while current.link != head :
		pre = current
		current = current.link
		if current.data == deleteData :  	# When middle node is found
			pre.link = current.link
			del(current)
			return

## Global Variables ##
memory = []
head, current, pre = None, None, None
dataArray = ["Dahyun", "Jungyeon", "Tzuyu", "Sana", "Jihyo"]

## Main Code ##
if __name__ == "__main__" :

	node = Node()		# First node
	node.data = dataArray[0]
	head = node
	node.link = head
	memory.append(node)

	for data in dataArray[1:] :	# From the second node onward
		pre = node
		node = Node()
		node.data = data
		pre.link = node
		node.link = head
		memory.append(node)

	printNodes(head)

	deleteNode("Dahyun")
	printNodes(head)

	deleteNode("Tzuyu")
	printNodes(head)

	deleteNode("Jihyo")
	printNodes(head)

	deleteNode("Jaenam")
	printNodes(head)

Code05-07.py

이중 연결 리스트에서 노드를 삭제합니다

## 클래스와 함수 선언 부분 ##
class Node() :
    def __init__ (self) :
        self.data = None
        self.link = None

def printNodes(start):

	current = start
	if current.link == None :
		return
	print(current.data, end=' ')
	while current.link != start:
		current = current.link
		print(current.data, end=' ')
	print()

def findNode(findData) :

	global memory, head, current, pre

	current = head
	if current.data == findData :
		return current
	while current.link != head :
		current = current.link
		if current.data == findData :
			return current
	return Node()	# 빈 노드 반환

## 전역 변수 선언 부분 ##
memory = []
head, current, pre = None, None, None
dataArray = ["다현", "정연", "쯔위", "사나", "지효"]

## 메인 코드 부분 ##

if __name__ == "__main__" :

	node = Node()		# 첫 번째 노드
	node.data = dataArray[0]
	head = node
	node.link = head
	memory.append(node)

	for data in dataArray[1:] :	# 두 번째 이후 노드
		pre = node
		node = Node()
		node.data = data
		pre.link = node
		node.link = head
		memory.append(node)

	printNodes(head)

	fNode = findNode("다현")
	print(fNode.data)

	fNode = findNode("쯔위")
	print(fNode.data)

	fNode = findNode("재남")
	print(fNode.data)

Code05-07.py

Deletes nodes from a doubly linked list

## Class & Function Declarations ##
class Node() :
    def __init__ (self) :
        self.data = None
        self.link = None

def printNodes(start):

	current = start
	if current.link == None :
		return
	print(current.data, end=' ')
	while current.link != start:
		current = current.link
		print(current.data, end=' ')
	print()

def findNode(findData) :

	global memory, head, current, pre

	current = head
	if current.data == findData :
		return current
	while current.link != head :
		current = current.link
		if current.data == findData :
			return current
	return Node()	# Return empty node

## Global Variables ##
memory = []
head, current, pre = None, None, None
dataArray = ["Dahyun", "Jungyeon", "Tzuyu", "Sana", "Jihyo"]

## Main Code ##
if __name__ == "__main__" :

	node = Node()		# First node
	node.data = dataArray[0]
	head = node
	node.link = head
	memory.append(node)

	for data in dataArray[1:] :	# From the second node onward
		pre = node
		node = Node()
		node.data = data
		pre.link = node
		node.link = head
		memory.append(node)

	printNodes(head)

	fNode = findNode("Dahyun")
	print(fNode.data)

	fNode = findNode("Tzuyu")
	print(fNode.data)

	fNode = findNode("Jaenam")
	print(fNode.data)

Code05-08.py

랜덤 데이터로 이중 연결 리스트를 생성합니다

import random

## 클래스와 함수 선언 부분 ##
class Node() :
	def __init__ (self) :
		self.data = None
		self.link = None

def printNodes(start):

	current = start
	if current.link == None :
		return
	print(current.data, end=' ')
	while current.link != start:
		current = current.link
		print(current.data, end=' ')
	print()

def  countOddEven() :

	global memory, head, current, pre

	odd, even = 0, 0
	if head == None :
		return False

	current = head
	while True:
		if current.data % 2 == 0:
			even += 1
		else :
			odd += 1
		if current.link == head :
			break;
		current = current.link

	return odd, even

def makeZeroNumber(odd, even):

	if odd > even :
		reminder = 1
	else :
		reminder = 0

	current = head
	while True:
		if current.data % 2 == reminder:
			current.data *= -1
		if current.link == head :
			break;
		current = current.link

## 전역 변수 선언 부분 ##
memory = []
head, current, pre = None, None, None

## 메인 코드 부분 ##

if __name__ == "__main__" :

	dataArray = []
	for _ in range(7) :
		dataArray.append(random.randint(1, 100))

	node = Node()
	node.data = dataArray[0]
	head = node
	node.link = head
	memory.append(node)

	for data in dataArray[1:] :
		pre = node
		node = Node()
		node.data = data
		pre.link = node
		node.link = head
		memory.append(node)

	printNodes(head)

	oddCount, evenCount = countOddEven()
	print('홀수 -->', oddCount, '\t', '짝수 -->', evenCount)

	makeZeroNumber(oddCount, evenCount)
	printNodes(head)

Code05-08.py

Creates a doubly linked list with random data

import random

## Class & Function Declarations ##
class Node() :
	def __init__ (self) :
		self.data = None
		self.link = None

def printNodes(start):

	current = start
	if current.link == None :
		return
	print(current.data, end=' ')
	while current.link != start:
		current = current.link
		print(current.data, end=' ')
	print()

def  countOddEven() :

	global memory, head, current, pre

	odd, even = 0, 0
	if head == None :
		return False

	current = head
	while True:
		if current.data % 2 == 0:
			even += 1
		else :
			odd += 1
		if current.link == head :
			break;
		current = current.link

	return odd, even

def makeZeroNumber(odd, even):

	if odd > even :
		reminder = 1
	else :
		reminder = 0

	current = head
	while True:
		if current.data % 2 == reminder:
			current.data *= -1
		if current.link == head :
			break;
		current = current.link

## Global Variables ##
memory = []
head, current, pre = None, None, None

## Main Code ##
if __name__ == "__main__" :

	dataArray = []
	for _ in range(7) :
		dataArray.append(random.randint(1, 100))

	node = Node()
	node.data = dataArray[0]
	head = node
	node.link = head
	memory.append(node)

	for data in dataArray[1:] :
		pre = node
		node = Node()
		node.data = data
		pre.link = node
		node.link = head
		memory.append(node)

	printNodes(head)

	oddCount, evenCount = countOddEven()
	print('odd -->', oddCount, '\t', 'even -->', evenCount)

	makeZeroNumber(oddCount, evenCount)
	printNodes(head)

📗 응용 예제 (Ex)

📗 Applied Examples (Ex)

EX05-01.py

원형 연결 리스트 응용: 랜덤 데이터 정렬 삽입

import random
import math

## 클래스와 함수 선언 부분 ##
class Node() :
	def __init__ (self) :
		self.data = None
		self.link = None

def printStores(start) :

	current = start
	if current == None :
		return

	while current.link != head:
		current = current.link
		x, y = current.data[1:]
		print(current.data[0], '편의점, 거리:', math.sqrt(x*x + y*y))
	print()

def  makeStoreList(store) :

	global memory, head, current, pre

	node = Node()
	node.data = store
	memory.append(node)

	if head == None : # 첫 번째 편의점
		head = node
		node.link = head
		return

	# 새 편의점이 첫 번째 편의점보다 가까우면 첫 편의점으로 만듦
	nodeX, nodeY = node.data[1:]
	nodeDist = math.sqrt(nodeX*nodeX + nodeY*nodeY)
	headX, headY = head.data[1:]
	headDist = math.sqrt(headX*headX + headY*headY)

	if headDist > nodeDist :	# 헤드 앞에 삽입
		node.link = head
		last = head
		while last.link != head :
			last = last.link
		last.link = node
		head = node
		return

	current = head		# 중간에 데이터를 넣을 경우
	while current.link != head :
		pre = current
		current = current.link
		currX, currY = current.data[1:]
		currDist = math.sqrt(currX*currX + currY*currY)
		if currDist > nodeDist :
			pre.link = node
			node.link = current
			return

	current.link = node
	node.link = head

## 전역 변수 선언 부분 ##
memory = []
head, current, pre = None, None, None

## 메인 코드 부분 ##

if __name__ == "__main__" :

	storeArray = []
	storeName = 'A'
	for _ in range(10) :
		store = (storeName, random.randint(1, 100), random.randint(1, 100) )
		storeArray.append(store)
		storeName = chr(ord(storeName) + 1)	# 편의점 이름을 A->B->C… 으로 변경

	for store in storeArray :
		makeStoreList(store)

	printStores(head)

EX05-01.py

Circular linked list application: sorted insertion of random data

import random
import math

## Class & Function Declarations ##
class Node() :
	def __init__ (self) :
		self.data = None
		self.link = None

def printStores(start) :

	current = start
	if current == None :
		return

	while current.link != head:
		current = current.link
		x, y = current.data[1:]
		print(current.data[0], 'Store, distance:', math.sqrt(x*x + y*y))
	print()

def  makeStoreList(store) :

	global memory, head, current, pre

	node = Node()
	node.data = store
	memory.append(node)

	if head == None : # First store
		head = node
		node.link = head
		return

	# If new store is closer than first, make it first
	nodeX, nodeY = node.data[1:]
	nodeDist = math.sqrt(nodeX*nodeX + nodeY*nodeY)
	headX, headY = head.data[1:]
	headDist = math.sqrt(headX*headX + headY*headY)

	if headDist > nodeDist :	# Insert before head
		node.link = head
		last = head
		while last.link != head :
			last = last.link
		last.link = node
		head = node
		return

	current = head		# When inserting data in the middle
	while current.link != head :
		pre = current
		current = current.link
		currX, currY = current.data[1:]
		currDist = math.sqrt(currX*currX + currY*currY)
		if currDist > nodeDist :
			pre.link = node
			node.link = current
			return

	current.link = node
	node.link = head

## Global Variables ##
memory = []
head, current, pre = None, None, None

## Main Code ##
if __name__ == "__main__" :

	storeArray = []
	storeName = 'A'
	for _ in range(10) :
		store = (storeName, random.randint(1, 100), random.randint(1, 100) )
		storeArray.append(store)
		storeName = chr(ord(storeName) + 1)	# Change store name A->B->C...

	for store in storeArray :
		makeStoreList(store)

	printStores(head)

Ex05-02.py

이중 연결 리스트 응용: 양방향 순회

## 클래스와 함수 선언 부분 ##
class Node2() :
	def __init__ (self) :
		self.plink = None		# 앞쪽 링크
		self.data = None
		self.nlink = None		# 뒤쪽 링크

def printNodes(start):

	current = start
	if current.nlink == None :
		return
	print("정방향 --> ", end=' ')
	print(current.data, end=' ')
	while current.nlink != None:
		current = current.nlink
		print(current.data, end=' ')
	print()
	print("역방향 --> ", end=' ')
	print(current.data, end=' ')
	while current.plink != None:
		current = current.plink
		print(current.data, end=' ')

## 전역 변수 선언 부분 ##
memory = []
head, current, pre = None, None, None
dataArray = ["다현", "정연", "쯔위", "사나", "지효"]

## 메인 코드 부분 ##

if __name__ == "__main__" :

	node = Node2()			# 첫 번째 노드
	node.data = dataArray[0]
	head = node
	memory.append(node)

	for data in dataArray[1:] :		# 두 번째 이후 노드
		pre = node
		node = Node2()
		node.data = data
		pre.nlink = node
		node.plink = pre
		memory.append(node)

	printNodes(head)

Ex05-02.py

Doubly linked list application: bidirectional traversal

## Class & Function Declarations ##
class Node2() :
	def __init__ (self) :
		self.plink = None		# previous link
		self.data = None
		self.nlink = None		# next link

def printNodes(start):

	current = start
	if current.nlink == None :
		return
	print("forward --> ", end=' ')
	print(current.data, end=' ')
	while current.nlink != None:
		current = current.nlink
		print(current.data, end=' ')
	print()
	print("reverse --> ", end=' ')
	print(current.data, end=' ')
	while current.plink != None:
		current = current.plink
		print(current.data, end=' ')

## Global Variables ##
memory = []
head, current, pre = None, None, None
dataArray = ["Dahyun", "Jungyeon", "Tzuyu", "Sana", "Jihyo"]

## Main Code ##
if __name__ == "__main__" :

	node = Node2()			# First node
	node.data = dataArray[0]
	head = node
	memory.append(node)

	for data in dataArray[1:] :		# From the second node onward
		pre = node
		node = Node2()
		node.data = data
		pre.nlink = node
		node.plink = pre
		memory.append(node)

	printNodes(head)

📙 자가 실습 (Self)

📙 Self Practice (Self)

Self05-01.py

원형 연결 리스트를 직접 구현합니다

## 클래스 및 함수 선언부 ##
class Node() :
    def __init__ (self) :
        self.data = None
        self.link = None

def printNodes(start):

    current = start
    if current.link == None :
        return
    print(current.data, end=' ')
    while current.link != start:
        current = current.link
        print(current.data, end=' ')
    print()

def findNode(findData) :

    global memory, head, current, pre

    current = head
    if current.data == findData :
        print("# 첫 노드에서 찾음 #")
        return current
    while current.link != head :
        current = current.link
        if current.data == findData :
            print("# 중간 노드에서 찾음 #")
            return current
    print("# 찾는 노드가 없음 #")
    return Node() # 빈 노드 반환

## 전역 변수 선언부
memory = []
head, current, pre = None, None, None
dataArray = ["다현", "정연", "쯔위", "사나", "지효"]

## 메인 코드부

if __name__ == "__main__" :

    # 첫번째 노드
    node = Node()
    node.data = dataArray[0]
    head = node
    node.link = head
    memory.append(node)

    # 두번째 노드 부터
    for data in dataArray[1:] :
        pre = node
        node = Node()
        node.data = data
        pre.link = node
        node.link = head
        memory.append(node)

    printNodes(head)

    fNode = findNode("다현")
    print(fNode.data)

    fNode = findNode("쯔위")
    print(fNode.data)

    fNode = findNode("재남")
    print(fNode.data)

Self05-01.py

Implements a circular linked list yourself

## Class & Function Declarations ##
class Node() :
    def __init__ (self) :
        self.data = None
        self.link = None

def printNodes(start):

    current = start
    if current.link == None :
        return
    print(current.data, end=' ')
    while current.link != start:
        current = current.link
        print(current.data, end=' ')
    print()

def findNode(findData) :

    global memory, head, current, pre

    current = head
    if current.data == findData :
        print("# Found at first node #")
        return current
    while current.link != head :
        current = current.link
        if current.data == findData :
            print("# Found at middle node #")
            return current
    print("# Node not found #")
    return Node() # Return empty node

## Global Variables
memory = []
head, current, pre = None, None, None
dataArray = ["Dahyun", "Jungyeon", "Tzuyu", "Sana", "Jihyo"]

## Main Code
if __name__ == "__main__" :

    # First node
    node = Node()
    node.data = dataArray[0]
    head = node
    node.link = head
    memory.append(node)

    # From the second node onward
    for data in dataArray[1:] :
        pre = node
        node = Node()
        node.data = data
        pre.link = node
        node.link = head
        memory.append(node)

    printNodes(head)

    fNode = findNode("Dahyun")
    print(fNode.data)

    fNode = findNode("Tzuyu")
    print(fNode.data)

    fNode = findNode("Jaenam")
    print(fNode.data)

Self05-02.py

이중 연결 리스트를 직접 구현합니다

import random

## 클래스 및 함수 선언부 ##
class Node() :
    def __init__ (self) :
        self.data = None
        self.link = None

def printNodes(start) :

    current = start
    if current == None :
        return
    print(current.data, end=' ')
    while current.link != head:
        current = current.link
        print(current.data, end=' ')
    print()

def  countOddEven() :

    global memory, head, current, pre

    plus, minus = 0, 0
    if head == None :
        return False

    current = head
    while True:
        if current.data > 0:
            plus += 1
        elif  current.data < 0:
            minus += 1
        if current.link == head :
            break
        current = current.link

    return plus, minus

def makeZeroNumber(odd, even):

    if odd > even :
        reminder = 1
    else :
        reminder = 0

    current = head
    while True:
        current.data *= -1
        if current.link == head :
            break
        current = current.link

## 전역 변수 선언부
memory = []
head, current, pre = None, None, None

## 메인 코드부

if __name__ == "__main__" :

    dataArray = []
    for _ in range(7) :
        dataArray.append(random.randint(-100,100))

    node = Node()
    node.data = dataArray[0]
    head = node
    node.link = head
    memory.append(node)

    for data in dataArray[1:] :
        pre = node
        node = Node()
        node.data = data
        pre.link = node
        node.link = head
        memory.append(node)

    printNodes(head)

    plusCount, minusCount = countOddEven()
    print('양수 -->', plusCount, '\t', '음수 -->', minusCount)

    makeZeroNumber(plusCount, minusCount)
    printNodes(head)