
"""simple docstring"""

# This Python program implements an optimal binary search tree (abbreviated BST)
# building dynamic programming algorithm that delivers O(n^2) performance.
#
# The goal of the optimal BST problem is to build a low-cost BST for a
# given set of nodes, each with its own key and frequency. The frequency
# of the node is defined as how many time the node is being searched.
# The search cost of binary search tree is given by this formula:
#
# cost(1, n) = sum{i = 1 to n}((depth(node_i) + 1) * node_i_freq)
#
# where n is number of nodes in the BST. The characteristic of low-cost
# BSTs is having a faster overall search time than other implementations.
# The reason for their fast search time is that the nodes with high
# frequencies will be placed near the root of the tree while the nodes
# with low frequencies will be placed near the leaves of the tree thus
# reducing search time in the most frequent instances.
import sys
from random import randint






class 			_lowercase  :




	def __init__(					self						,					UpperCAmelCase_						,					UpperCAmelCase_   )						->				Optional[int]:
			lowerCamelCase	:     Optional[int]            =       key
			lowerCamelCase	:     Union[str, Any]            =       freq




	def __str__(					self   )						->				Tuple:
			return F"""Node(key={self.key}, freq={self.freq})"""


def 						UpperCAmelCase   (						a_,		a_,		a_,		a_,		a_,		a_     ):





		'''simple docstring'''


		if i > j or i < 0 or j > len(_snake_case     ) - 1:
				return

		lowerCamelCase	:     Dict            =       root[i][j]
		if parent == -1:  # root does not have a parent
				print(F"""{key[node]} is the root of the binary search tree."""     )
		elif is_left:
				print(F"""{key[node]} is the left child of key {parent}."""     )
		else:
				print(F"""{key[node]} is the right child of key {parent}."""     )

		print_binary_search_tree(_snake_case,		_snake_case,		_snake_case,		node - 1,		key[node],		_snake_case     )
		print_binary_search_tree(_snake_case,		_snake_case,		node + 1,		_snake_case,		key[node],		_snake_case     )
def 						UpperCAmelCase   (						a_     ):





		'''simple docstring'''


		nodes.sort(key=lambda a_     : node.key     )

		lowerCamelCase	:     Any            =       len(_snake_case     )

		lowerCamelCase	:     Union[str, Any]            =       [nodes[i].key for i in range(_snake_case     )]
		lowerCamelCase	:     str            =       [nodes[i].freq for i in range(_snake_case     )]

		# This 2D array stores the overall tree cost (which's as minimized as possible);
		# for a single key, cost is equal to frequency of the key.
		lowerCamelCase	:     Optional[Any]            =       [[freqs[i] if i == j else 0 for j in range(_snake_case     )] for i in range(_snake_case     )]
		# sum[i][j] stores the sum of key frequencies between i and j inclusive in nodes
		# array
		lowerCamelCase	:     Tuple            =       [[freqs[i] if i == j else 0 for j in range(_snake_case     )] for i in range(_snake_case     )]
		# stores tree roots that will be used later for constructing binary search tree
		lowerCamelCase	:     Dict            =       [[i if i == j else 0 for j in range(_snake_case     )] for i in range(_snake_case     )]

		for interval_length in range(2,		n + 1     ):
				for i in range(n - interval_length + 1     ):
						lowerCamelCase	:     Optional[int]            =       i + interval_length - 1

						lowerCamelCase	:     Union[str, Any]            =       sys.maxsize  # set the value to "infinity"
						lowerCamelCase	:     Any            =       total[i][j - 1] + freqs[j]

						# Apply Knuth's optimization
						# Loop without optimization: for r in range(i, j + 1):
						for r in range(root[i][j - 1],		root[i + 1][j] + 1     ):  # r is a temporal root
								lowerCamelCase	:     Union[str, Any]            =       dp[i][r - 1] if r != i else 0  # optimal cost for left subtree
								lowerCamelCase	:     Optional[Any]            =       dp[r + 1][j] if r != j else 0  # optimal cost for right subtree
								lowerCamelCase	:     Dict            =       left + total[i][j] + right

								if dp[i][j] > cost:
										lowerCamelCase	:     str            =       cost
										lowerCamelCase	:     List[str]            =       r

		print('Binary search tree nodes:'     )
		for node in nodes:
				print(_snake_case     )

		print(F"""\nThe cost of optimal BST for given tree nodes is {dp[0][n - 1]}."""     )
		print_binary_search_tree(_snake_case,		_snake_case,		0,		n - 1,		-1,		_snake_case     )
def 						UpperCAmelCase   (						):





		'''simple docstring'''


		lowerCamelCase	:     Any            =       [Node(_snake_case,		randint(1,		50     )     ) for i in range(10,		0,		-1     )]
		find_optimal_binary_search_tree(_snake_case     )


if __name__ == "__main__":
					main()












import os
import sys

from . import rsa_key_generator as rkg

UpperCAmelCase_    =128
UpperCAmelCase_    =256



def    UpperCAmelCase							(  _snake_case    ,			_snake_case = DEFAULT_BLOCK_SIZE				):
							lowerCAmelCase =		message.encode('''ascii'''				)

							lowerCAmelCase =		[]
							for block_start in range(0    ,			len(_snake_case				)    ,			_snake_case				):
														lowerCAmelCase =		0
														for i in range(_snake_case    ,			min(block_start + block_size    ,			len(_snake_case				)				)				):
																					block_int += message_bytes[i] * (BYTE_SIZE ** (i % block_size))
														block_ints.append(_snake_case				)
							return block_ints



def    UpperCAmelCase							(  _snake_case    ,			_snake_case    ,			_snake_case = DEFAULT_BLOCK_SIZE				):
							lowerCAmelCase =		[]
							for block_int in block_ints:
														lowerCAmelCase =		[]
														for i in range(block_size - 1    ,			-1    ,			-1				):
																					if len(_snake_case				) + i < message_length:
																												lowerCAmelCase =		block_int // (BYTE_SIZE**i)
																												lowerCAmelCase =		block_int % (BYTE_SIZE**i)
																												block_message.insert(0    ,			chr(_snake_case				)				)
														message.extend(_snake_case				)
							return "".join(_snake_case				)



def    UpperCAmelCase							(  _snake_case    ,			_snake_case    ,			_snake_case = DEFAULT_BLOCK_SIZE				):
							lowerCAmelCase =		[]
							lowerCAmelCase ,  lowerCAmelCase =		key

							for block in get_blocks_from_text(_snake_case    ,			_snake_case				):
														encrypted_blocks.append(pow(_snake_case    ,			_snake_case    ,			_snake_case				)				)
							return encrypted_blocks



def    UpperCAmelCase							(  _snake_case    ,			_snake_case    ,			_snake_case    ,			_snake_case = DEFAULT_BLOCK_SIZE    ,			):
							lowerCAmelCase =		[]
							lowerCAmelCase ,  lowerCAmelCase =		key
							for block in encrypted_blocks:
														decrypted_blocks.append(pow(_snake_case    ,			_snake_case    ,			_snake_case				)				)
							return get_text_from_blocks(_snake_case    ,			_snake_case    ,			_snake_case				)



def    UpperCAmelCase							(  _snake_case				):
							with open(_snake_case				) as fo:
														lowerCAmelCase =		fo.read()
							lowerCAmelCase ,  lowerCAmelCase ,  lowerCAmelCase =		content.split(''','''				)
							return (int(_snake_case				), int(_snake_case				), int(_snake_case				))



def    UpperCAmelCase							(  _snake_case    ,			_snake_case    ,			_snake_case    ,			_snake_case = DEFAULT_BLOCK_SIZE    ,			):
							lowerCAmelCase ,  lowerCAmelCase ,  lowerCAmelCase =		read_key_file(_snake_case				)
							if key_size < block_size * 8:
														sys.exit(
														    '''ERROR: Block size is {} bits and key size is {} bits. The RSA cipher '''
														    '''requires the block size to be equal to or greater than the key size. '''
														    '''Either decrease the block size or use different keys.'''.format(
														        block_size * 8    ,			_snake_case				)				)

							lowerCAmelCase =		[str(_snake_case				) for i in encrypt_message(_snake_case    ,			(n, e)    ,			_snake_case				)]

							lowerCAmelCase =		''','''.join(_snake_case				)
							lowerCAmelCase =		F"""{len(_snake_case				)}_{block_size}_{encrypted_content}"""
							with open(_snake_case    ,			'''w'''				) as fo:
														fo.write(_snake_case				)
							return encrypted_content



def    UpperCAmelCase							(  _snake_case    ,			_snake_case				):
							lowerCAmelCase ,  lowerCAmelCase ,  lowerCAmelCase =		read_key_file(_snake_case				)
							with open(_snake_case				) as fo:
														lowerCAmelCase =		fo.read()
							lowerCAmelCase ,  lowerCAmelCase ,  lowerCAmelCase =		content.split('''_'''				)
							lowerCAmelCase =		int(_snake_case				)
							lowerCAmelCase =		int(_snake_case				)

							if key_size < block_size * 8:
														sys.exit(
														    '''ERROR: Block size is {} bits and key size is {} bits. The RSA cipher '''
														    '''requires the block size to be equal to or greater than the key size. '''
														    '''Did you specify the correct key file and encrypted file?'''.format(
														        block_size * 8    ,			_snake_case				)				)

							lowerCAmelCase =		[]
							for block in encrypted_message.split(''','''				):
														encrypted_blocks.append(int(_snake_case				)				)

							return decrypt_message(_snake_case    ,			_snake_case    ,			(n, d)    ,			_snake_case				)



def    UpperCAmelCase							(  ):
							lowerCAmelCase =		'''encrypted_file.txt'''
							lowerCAmelCase =		input(R'''Encrypt\Decrypt [e\d]: '''				)

							if response.lower().startswith('''e'''				):
														lowerCAmelCase =		'''encrypt'''
							elif response.lower().startswith('''d'''				):
														lowerCAmelCase =		'''decrypt'''

							if mode == "encrypt":
														if not os.path.exists('''rsa_pubkey.txt'''				):
																					rkg.make_key_files('''rsa'''    ,			1024				)

														lowerCAmelCase =		input('''\nEnter message: '''				)
														lowerCAmelCase =		'''rsa_pubkey.txt'''
														print(F"""Encrypting and writing to {filename}..."""				)
														lowerCAmelCase =		encrypt_and_write_to_file(_snake_case    ,			_snake_case    ,			_snake_case				)

														print('''\nEncrypted text:'''				)
														print(_snake_case				)

							elif mode == "decrypt":
														lowerCAmelCase =		'''rsa_privkey.txt'''
														print(F"""Reading from {filename} and decrypting..."""				)
														lowerCAmelCase =		read_from_file_and_decrypt(_snake_case    ,			_snake_case				)
														print('''writing decryption to rsa_decryption.txt...'''				)
														with open('''rsa_decryption.txt'''    ,			'''w'''				) as dec:
																					dec.write(_snake_case				)

														print('''\nDecryption:'''				)
														print(_snake_case				)


if __name__ == "__main__":
		main()



