125 lines
2.9 KiB
Python
125 lines
2.9 KiB
Python
class Bt_node:
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def __init__(self, item):
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self.item = item
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self.left = None
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self.right = None
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class Stack_node:
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def __init__(self, btnode):
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self.btnode = btnode
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self.next = None
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class Stack:
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def __init__(self):
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self.top = None
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def create_bt_node(item):
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return Bt_node(item)
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def push(stack, node):
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temp = Stack_node(node)
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if stack.top is None:
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stack.top = temp
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temp.next = None
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else:
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temp.next = stack.top
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stack.top = temp
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def pop(stack):
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if stack.top is None:
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return None
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temp = stack.top.next
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ptr = stack.top.btnode
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stack.top = temp
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return ptr
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def print_tree(node):
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if node is None:
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return
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print_tree(node.left)
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print(node.item, end=" ")
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print_tree(node.right)
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def create_tree():
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stack = Stack()
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root = None
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print("Input an integer that you want to add to the binary tree. Any Alpha value will be treated as NULL.")
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try:
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item = input("Enter an integer value for the root: ")
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root = create_bt_node(int(item))
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push(stack, root)
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except ValueError:
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return None
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while True:
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temp = pop(stack)
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if temp is None:
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break
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try:
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item = input(f"Enter an integer value for the Left child of {temp.item}: ")
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temp.left = create_bt_node(int(item))
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except ValueError:
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temp.left = None
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try:
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item = input(f"Enter an integer value for the Right child of {temp.item}: ")
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temp.right = create_bt_node(int(item))
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except ValueError:
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temp.right = None
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if temp.right is not None:
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push(stack, temp.right)
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if temp.left is not None:
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push(stack, temp.left)
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return root
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def remove_all(node):
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if node is not None:
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remove_all(node.left)
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remove_all(node.right)
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node.left = None
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node.right = None
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def max_depth(node):
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raise NotImplementedError
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def main():
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root = None
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print("1: Create a binary tree.")
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print("2: Find the maximum depth of the binary tree.")
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print("0: Quit;")
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while True:
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try:
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c = int(input("\nPlease input your choice(1/2/0): "))
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if c == 1:
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root = None # Clear existing tree
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root = create_tree()
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print("The resulting binary tree is: ", end="")
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print_tree(root)
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print()
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elif c == 2:
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depth = max_depth(root)
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print(f"The maximum depth of the binary tree is: {depth}")
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root = None
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elif c == 0:
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if root:
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remove_all(root)
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break
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else:
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print("Choice unknown;")
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except ValueError:
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continue
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if __name__ == "__main__":
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main() |