Question

Python question

Your code can make use of any of the BinarySearchTree ADT methods: BinarySearchTree(), insert_left(), insert_right(), get_left(), get_right(), set_left(), set_right(),get_data(), set_data(), search(), __contains__ and insert().

Define a function called create_bst_from_list(values) which takes a list of values as a parameter. The function should create a binary search tree by using the insert() method.

Note: You can assume that the BinarySearchTree class is given and the parameter list is not empty.

For example:

Test	Result
tree = create_bst_from_list([7, 12, 4, 9, 20]) print_tree(tree, 0)	7 (L) 4 (R) 12 (L) 9 (R) 20
tree = create_bst_from_list([8, 3, 1, 6, 4, 25, 78]) print_tree(tree, 0)	8 (L) 3 (L) 1 (R) 6 (L) 4 (R) 25 (R) 78

class BinarySearchTree:
    def __init__(self, data, left=None, right=None):
        self.__data = data
        self.__left = left
        self.__right = right
    def insert_left(self, new_data):
        if self.__left == None:
            self.__left = BinarySearchTree(new_data)
        else:
            tree = BinarySearchTree(new_data, left=self.__left)
            self.__left = tree
    def insert_right(self, new_data):
        if self.__right == None:
            self.__right = BinarySearchTree(new_data)
        else:
            tree = BinarySearchTree(new_data, right=self.__right)
            self.__right = tree
    def get_left(self):
        return self.__left
    def get_right(self):
        return self.__right
    def set_left(self, left):
        self.__left = left
    def set_right(self, right):
        self.__right = right
    def set_data(self, data):
        self.__data = data
    def get_data(self):
        return self.__data

I need answers soon. Please!

Answer 1

Here is the code,

class BinarySearchTree:
    def __init__(self, data, left=None, right=None):
        self.__data = data
        self.__left = left
        self.__right = right
    def insert_left(self, new_data):
        if self.__left == None:
            self.__left = BinarySearchTree(new_data)
        else:
            tree = BinarySearchTree(new_data, left=self.__left)
            self.__left = tree
    def insert_right(self, new_data):
        if self.__right == None:
            self.__right = BinarySearchTree(new_data)
        else:
            tree = BinarySearchTree(new_data, right=self.__right)
            self.__right = tree
    def get_left(self):
        return self.__left
    def get_right(self):
        return self.__right
    def set_left(self, left):
        self.__left = left
    def set_right(self, right):
        self.__right = right
    def set_data(self, data):
        self.__data = data
    def get_data(self):
        return self.__data
        
    def insertNode(self, currentNode, val):
        if(val <= currentNode.__data):
            if(currentNode.__left):
                self.insertNode(currentNode.__left, val)
            else:
                currentNode.__left = BinarySearchTree(val)
        elif(val > currentNode.__data):
            if(currentNode.__right):
                self.insertNode(currentNode.__right, val)
            else:
                currentNode.__right = BinarySearchTree(val)
                
    def printLevelOrder(self):
        if self is None:
            return
        queue = []
        queue.append(self)
        levelNumber = 0
        while(len(queue) > 0):
            level = ""
            for i in range(0, len(queue)):
                node = queue.pop(0)
                if node is None:
                    level = level + "X "
                    continue
                level = level + str(node.__data) + " "
                queue.append(node.__left)
                queue.append(node.__right)
            print("Level ",levelNumber," : ",level)
            level = ""
            levelNumber += 1
        
def create_bst_from_list(values):
    tree = None
    for val in values:
        if tree is None:
            tree = BinarySearchTree(val)
        else:
            tree.insertNode(tree, val)
    return tree
        
if __name__ == "__main__": 
    values = [8, 3, 1, 6, 4, 25, 78]
    tree = create_bst_from_list(values)
    tree.printLevelOrder()

OUTPUT:

X -> means empty space

This is how the tree would look like on paper:

If you have any doubts then put in the comments. Also, do upvote the solution.