使用BFS遍歷建立樹的映象副本的Python程式
當需要建立一個樹的映象副本並使用廣度優先搜尋顯示它時,會建立一個帶有方法的二叉樹類,這些方法可以設定根元素,將元素插入左側,將元素插入右側,搜尋特定元素,執行後序遍歷等等。建立類的例項,可以使用它來訪問方法。
以下是相同的演示 -
示例
class BinaryTree_struct:
def __init__(self, key=None):
self.key = key
self.left = None
self.right = None
def set_root(self, key):
self.key = key
def insert_to_left(self, new_node):
self.left = new_node
def insert_to_right(self, new_node):
self.right = new_node
def search_elem(self, key):
if self.key == key:
return self
if self.left is not None:
temp = self.left.search_elem(key)
if temp is not None:
return temp
if self.right is not None:
temp = self.right.search_elem(key)
return temp
return None
def copy_mirror(self):
mirror = BinaryTree_struct(self.key)
if self.right is not None:
mirror.left = self.right.copy_mirror()
if self.left is not None:
mirror.right = self.left.copy_mirror()
return mirror
def bfs(self):
queue = [self]
while queue != []:
popped = queue.pop(0)
if popped.left is not None:
queue.append(popped.left)
if popped.right is not None:
queue.append(popped.right)
print(popped.key, end=' ')
my_instance = None
print('Menu (this assumes no duplicate keys)')
print('insert <data> at root')
print('insert <data> left of <data>')
print('insert <data> right of <data>')
print('mirror')
print('quit')
while True:
my_input = input('What operation would you do ? ').split()
operation = my_input[0].strip().lower()
if operation == 'insert':
data = int(my_input[1])
new_node = BinaryTree_struct(data)
suboperation = my_input[2].strip().lower()
if suboperation == 'at':
my_instance = new_node
else:
position = my_input[4].strip().lower()
key = int(position)
ref_node = None
if my_instance is not None:
ref_node = my_instance.search_elem(key)
if ref_node is None:
print('No such key exists..')
continue
if suboperation == 'left':
ref_node.insert_to_left(new_node)
elif suboperation == 'right':
ref_node.insert_to_right(new_node)
elif operation == 'mirror':
if my_instance is not None:
print('Creating a mirror copy...')
mirror = my_instance.copy_mirror()
print('The breadth first search traversal of original tree is : ')
my_instance.bfs()
print()
print('The breadth first traversal of mirror is : ')
mirror.bfs()
print()
elif operation == 'quit':
break輸出
Menu (this assumes no duplicate keys) insert <data> at root insert <data> left of <data> insert <data> right of <data> mirror quit What operation would you do ? insert 6 at root What operation would you do ? insert 9 left of 6 What operation would you do ? insert 4 right of 6 What operation would you do ? mirror Creating a mirror copy... The breadth first search traversal of original tree is : 6 9 4 The breadth first traversal of mirror is : 6 4 9 What operation would you do ?quit Use quit() or Ctrl-D (i.e. EOF) to exit
解釋
建立具有所需屬性的“BinaryTree_struct”類。
它有一個“init”函式,用於將左右節點賦值為“None”。
定義了一個“set_root”方法,用於幫助將根節點賦值給一個值。
它有一個“insert_to_left”方法,用於幫助將元素新增到樹的左節點。
它有一個“insert_to_right”方法,用於幫助將元素新增到樹的右節點。
它有一個“bfs”方法,用於幫助在樹上執行廣度優先搜尋遍歷。
定義了一個名為“search_elem”的方法,用於幫助搜尋特定元素。
它有一個“copy_mirror”方法,用於幫助建立二叉樹的副本。
建立一個例項並將其賦值為“None”。
獲取使用者輸入,以確定需要執行的操作。
根據使用者的選擇執行操作。
在控制檯上顯示相關的輸出。
廣告
資料結構
網路
關係資料庫管理系統 (RDBMS)
作業系統
Java
iOS
HTML
CSS
Android
Python
C語言程式設計
C++
C#
MongoDB
MySQL
Javascript
PHP