Question

Python question

Define a function called max_value_length(tree) that takes a Binary Tree object as a parameter and returns an integer that contains the longest character length of all the values in that tree. Use recursion.

For example, the character length of value 123 is 3, because there are three digits. The character length of value “Ruru” is 4, because it has four characters. Further, the max_value_length() function would return 4 if the only node values in the tree were 123 and “Ruru”, because 4 is greater than 3.

Note 1: You must use recursion to answer this question (i.e., not loops).
Note 2: Values in the tree are always treated as strings.

For example:

Test	Result
binary_tree = create_tree_from_nested_list([7, [2, [14, None, None], [5, None, None]], [9, None, [144, None, None]]]) print(max_value_length(binary_tree))	3
binary_tree = create_tree_from_nested_list(["Hoiho", ["Kaki", ["Takahe", None, None], None], ["Ruru", None, ["Moa", None, ["Piwaiwaka", None, None]]]]) print(max_value_length(binary_tree))	9
binary_tree = create_tree_from_nested_list([]) print(max_value_length(binary_tree))	0

Answer 1

Solution:

binary_tree = ["Hoiho", ["Kaki", ["Takahe", None, None], None], ["Ruru", None, ["Moa", None, ["Piwaiwaka", None, None]]]]

max=0 #intializing max variable to "0", this vriable is used to find maximmm size

def my_function(binary_tree):
global max #Accessing max variable out side this function

if(len(binary_tree) == 0): # if length of input list is empty ,then return
return
if(index_in_list(binary_tree, 1) and index_in_list(binary_tree, 2) ): # if statement to left and right childs
my_function(binary_tree[1]) #recursion with left child
my_function(binary_tree[2]) #recursion with right child
  
if binary_tree is not None: #length will not be calculated for None Type
if max < len(str(binary_tree[0])): # condition to compare and to assign maximum value
max = len(str(binary_tree[0]))

return max #return maximum value

def index_in_list(a_list, index): #if condition used to check wether the index exist or not
if a_list is not None: #if index exists and not None,then return True
return index < len(a_list)

my_function(binary_tree) #calling function

print(max) # finally printing max value

Code in python 3.8.1 IDLE:

Output:

List1: for the list  [7, [2, [14, None, None], [5, None, None]], [9, None, [144, None, None]]]

List2: for the list ["Hoiho", ["Kaki", ["Takahe", None, None], None], ["Ruru", None, ["Moa", None, ["Piwaiwaka", None, None]]]]

List3: for the list []