Merge branch 'TheAlgorithms:master' into master

Author: akshaybsh

.pre-commit-config.yaml

@@ -26,7 +26,7 @@ repos:
       - id: black
 
   - repo: https://github.com/codespell-project/codespell
-    rev: v2.2.5
+    rev: v2.2.6
     hooks:
       - id: codespell
         additional_dependencies:

DIRECTORY.md

@@ -556,7 +556,7 @@
   * [Bell Numbers](maths/bell_numbers.py)
   * [Binary Exp Mod](maths/binary_exp_mod.py)
   * [Binary Exponentiation](maths/binary_exponentiation.py)
-  * [Binary Exponentiation 3](maths/binary_exponentiation_3.py)
+  * [Binary Exponentiation 2](maths/binary_exponentiation_2.py)
   * [Binary Multiplication](maths/binary_multiplication.py)
   * [Binomial Coefficient](maths/binomial_coefficient.py)
   * [Binomial Distribution](maths/binomial_distribution.py)
@@ -588,7 +588,6 @@
   * [Find Min](maths/find_min.py)
   * [Floor](maths/floor.py)
   * [Gamma](maths/gamma.py)
-  * [Gamma Recursive](maths/gamma_recursive.py)
   * [Gaussian](maths/gaussian.py)
   * [Gaussian Error Linear Unit](maths/gaussian_error_linear_unit.py)
   * [Gcd Of N Numbers](maths/gcd_of_n_numbers.py)
@@ -723,6 +722,7 @@
   * Activation Functions
     * [Exponential Linear Unit](neural_network/activation_functions/exponential_linear_unit.py)
     * [Leaky Rectified Linear Unit](neural_network/activation_functions/leaky_rectified_linear_unit.py)
+    * [Mish](neural_network/activation_functions/mish.py)
     * [Rectified Linear Unit](neural_network/activation_functions/rectified_linear_unit.py)
     * [Scaled Exponential Linear Unit](neural_network/activation_functions/scaled_exponential_linear_unit.py)
     * [Sigmoid Linear Unit](neural_network/activation_functions/sigmoid_linear_unit.py)
@@ -748,6 +748,7 @@
   * [Linear Congruential Generator](other/linear_congruential_generator.py)
   * [Lru Cache](other/lru_cache.py)
   * [Magicdiamondpattern](other/magicdiamondpattern.py)
+  * [Majority Vote Algorithm](other/majority_vote_algorithm.py)
   * [Maximum Subsequence](other/maximum_subsequence.py)
   * [Nested Brackets](other/nested_brackets.py)
   * [Number Container System](other/number_container_system.py)
@@ -1196,7 +1197,6 @@
   * [Rabin Karp](strings/rabin_karp.py)
   * [Remove Duplicate](strings/remove_duplicate.py)
   * [Reverse Letters](strings/reverse_letters.py)
-  * [Reverse Long Words](strings/reverse_long_words.py)
   * [Reverse Words](strings/reverse_words.py)
   * [Snake Case To Camel Pascal Case](strings/snake_case_to_camel_pascal_case.py)
   * [Split](strings/split.py)

bit_manipulation/power_of_4.py

@@ -0,0 +1,67 @@
+"""
+
+Task:
+Given a positive int number. Return True if this number is power of 4
+or False otherwise.
+
+Implementation notes: Use bit manipulation.
+For example if the number is the power of 2 it's bits representation:
+n     = 0..100..00
+n - 1 = 0..011..11
+
+n & (n - 1) - no intersections = 0
+If the number is a power of 4 then it should be a power of 2
+and the set bit should be at an odd position.
+"""
+
+
+def power_of_4(number: int) -> bool:
+    """
+    Return True if this number is power of 4 or False otherwise.
+
+    >>> power_of_4(0)
+    Traceback (most recent call last):
+        ...
+    ValueError: number must be positive
+    >>> power_of_4(1)
+    True
+    >>> power_of_4(2)
+    False
+    >>> power_of_4(4)
+    True
+    >>> power_of_4(6)
+    False
+    >>> power_of_4(8)
+    False
+    >>> power_of_4(17)
+    False
+    >>> power_of_4(64)
+    True
+    >>> power_of_4(-1)
+    Traceback (most recent call last):
+        ...
+    ValueError: number must be positive
+    >>> power_of_4(1.2)
+    Traceback (most recent call last):
+        ...
+    TypeError: number must be an integer
+
+    """
+    if not isinstance(number, int):
+        raise TypeError("number must be an integer")
+    if number <= 0:
+        raise ValueError("number must be positive")
+    if number & (number - 1) == 0:
+        c = 0
+        while number:
+            c += 1
+            number >>= 1
+        return c % 2 == 1
+    else:
+        return False
+
+
+if __name__ == "__main__":
+    import doctest
+
+    doctest.testmod()

ciphers/fractionated_morse_cipher.py

@@ -0,0 +1,167 @@
+"""
+Python program for the Fractionated Morse Cipher.
+
+The Fractionated Morse cipher first converts the plaintext to Morse code,
+then enciphers fixed-size blocks of Morse code back to letters.
+This procedure means plaintext letters are mixed into the ciphertext letters,
+making it more secure than substitution ciphers.
+
+http://practicalcryptography.com/ciphers/fractionated-morse-cipher/
+"""
+import string
+
+MORSE_CODE_DICT = {
+    "A": ".-",
+    "B": "-...",
+    "C": "-.-.",
+    "D": "-..",
+    "E": ".",
+    "F": "..-.",
+    "G": "--.",
+    "H": "....",
+    "I": "..",
+    "J": ".---",
+    "K": "-.-",
+    "L": ".-..",
+    "M": "--",
+    "N": "-.",
+    "O": "---",
+    "P": ".--.",
+    "Q": "--.-",
+    "R": ".-.",
+    "S": "...",
+    "T": "-",
+    "U": "..-",
+    "V": "...-",
+    "W": ".--",
+    "X": "-..-",
+    "Y": "-.--",
+    "Z": "--..",
+    " ": "",
+}
+
+# Define possible trigrams of Morse code
+MORSE_COMBINATIONS = [
+    "...",
+    "..-",
+    "..x",
+    ".-.",
+    ".--",
+    ".-x",
+    ".x.",
+    ".x-",
+    ".xx",
+    "-..",
+    "-.-",
+    "-.x",
+    "--.",
+    "---",
+    "--x",
+    "-x.",
+    "-x-",
+    "-xx",
+    "x..",
+    "x.-",
+    "x.x",
+    "x-.",
+    "x--",
+    "x-x",
+    "xx.",
+    "xx-",
+    "xxx",
+]
+
+# Create a reverse dictionary for Morse code
+REVERSE_DICT = {value: key for key, value in MORSE_CODE_DICT.items()}
+
+
+def encode_to_morse(plaintext: str) -> str:
+    """Encode a plaintext message into Morse code.
+
+    Args:
+        plaintext: The plaintext message to encode.
+
+    Returns:
+        The Morse code representation of the plaintext message.
+
+    Example:
+        >>> encode_to_morse("defend the east")
+        '-..x.x..-.x.x-.x-..xx-x....x.xx.x.-x...x-'
+    """
+    return "x".join([MORSE_CODE_DICT.get(letter.upper(), "") for letter in plaintext])
+
+
+def encrypt_fractionated_morse(plaintext: str, key: str) -> str:
+    """Encrypt a plaintext message using Fractionated Morse Cipher.
+
+    Args:
+        plaintext: The plaintext message to encrypt.
+        key: The encryption key.
+
+    Returns:
+        The encrypted ciphertext.
+
+    Example:
+        >>> encrypt_fractionated_morse("defend the east","Roundtable")
+        'ESOAVVLJRSSTRX'
+
+    """
+    morse_code = encode_to_morse(plaintext)
+    key = key.upper() + string.ascii_uppercase
+    key = "".join(sorted(set(key), key=key.find))
+
+    # Ensure morse_code length is a multiple of 3
+    padding_length = 3 - (len(morse_code) % 3)
+    morse_code += "x" * padding_length
+
+    fractionated_morse_dict = {v: k for k, v in zip(key, MORSE_COMBINATIONS)}
+    fractionated_morse_dict["xxx"] = ""
+    encrypted_text = "".join(
+        [
+            fractionated_morse_dict[morse_code[i : i + 3]]
+            for i in range(0, len(morse_code), 3)
+        ]
+    )
+    return encrypted_text
+
+
+def decrypt_fractionated_morse(ciphertext: str, key: str) -> str:
+    """Decrypt a ciphertext message encrypted with Fractionated Morse Cipher.
+
+    Args:
+        ciphertext: The ciphertext message to decrypt.
+        key: The decryption key.
+
+    Returns:
+        The decrypted plaintext message.
+
+    Example:
+        >>> decrypt_fractionated_morse("ESOAVVLJRSSTRX","Roundtable")
+        'DEFEND THE EAST'
+    """
+    key = key.upper() + string.ascii_uppercase
+    key = "".join(sorted(set(key), key=key.find))
+
+    inverse_fractionated_morse_dict = dict(zip(key, MORSE_COMBINATIONS))
+    morse_code = "".join(
+        [inverse_fractionated_morse_dict.get(letter, "") for letter in ciphertext]
+    )
+    decrypted_text = "".join(
+        [REVERSE_DICT[code] for code in morse_code.split("x")]
+    ).strip()
+    return decrypted_text
+
+
+if __name__ == "__main__":
+    """
+    Example usage of Fractionated Morse Cipher.
+    """
+    plaintext = "defend the east"
+    print("Plain Text:", plaintext)
+    key = "ROUNDTABLE"
+
+    ciphertext = encrypt_fractionated_morse(plaintext, key)
+    print("Encrypted:", ciphertext)
+
+    decrypted_text = decrypt_fractionated_morse(ciphertext, key)
+    print("Decrypted:", decrypted_text)

computer_vision/cnn_classification.py.DISABLED.txt

@@ -11,10 +11,10 @@ Download dataset from :
 https://lhncbc.nlm.nih.gov/LHC-publications/pubs/TuberculosisChestXrayImageDataSets.html
 
 1. Download the dataset folder and create two folder training set and test set
-in the parent dataste folder
+in the parent dataset folder
 2. Move 30-40 image from both TB positive and TB Negative folder
 in the test set folder
-3. The labels of the iamges will be extracted from the folder name
+3. The labels of the images will be extracted from the folder name
 the image is present in.
 
 """

computer_vision/mosaic_augmentation.py

@@ -8,7 +8,7 @@
 import cv2
 import numpy as np
 
-# Parrameters
+# Parameters
 OUTPUT_SIZE = (720, 1280)  # Height, Width
 SCALE_RANGE = (0.4, 0.6)  # if height or width lower than this scale, drop it.
 FILTER_TINY_SCALE = 1 / 100

data_structures/arrays/equilibrium_index_in_array.py

@@ -0,0 +1,59 @@
+"""
+Find the Equilibrium Index of an Array.
+Reference: https://www.geeksforgeeks.org/equilibrium-index-of-an-array/
+
+Python doctests can be run with the following command:
+python -m doctest -v equilibrium_index.py
+
+Given a sequence arr[] of size n, this function returns
+an equilibrium index (if any) or -1 if no equilibrium index exists.
+
+The equilibrium index of an array is an index such that the sum of
+elements at lower indexes is equal to the sum of elements at higher indexes.
+
+
+
+Example Input:
+arr = [-7, 1, 5, 2, -4, 3, 0]
+Output: 3
+
+"""
+
+
+def equilibrium_index(arr: list[int], size: int) -> int:
+    """
+    Find the equilibrium index of an array.
+
+    Args:
+        arr : The input array of integers.
+        size : The size of the array.
+
+    Returns:
+        int: The equilibrium index or -1 if no equilibrium index exists.
+
+    Examples:
+        >>> equilibrium_index([-7, 1, 5, 2, -4, 3, 0], 7)
+        3
+        >>> equilibrium_index([1, 2, 3, 4, 5], 5)
+        -1
+        >>> equilibrium_index([1, 1, 1, 1, 1], 5)
+        2
+        >>> equilibrium_index([2, 4, 6, 8, 10, 3], 6)
+        -1
+    """
+    total_sum = sum(arr)
+    left_sum = 0
+
+    for i in range(size):
+        total_sum -= arr[i]
+        if left_sum == total_sum:
+            return i
+        left_sum += arr[i]
+
+    return -1
+
+
+if __name__ == "__main__":
+    import doctest
+
+    doctest.testmod()

divide_and_conquer/strassen_matrix_multiplication.py

@@ -74,7 +74,7 @@ def print_matrix(matrix: list) -> None:
 def actual_strassen(matrix_a: list, matrix_b: list) -> list:
     """
     Recursive function to calculate the product of two matrices, using the Strassen
-    Algorithm.  It only supports even length matrices.
+    Algorithm. It only supports square matrices of any size that is a power of 2.
     """
     if matrix_dimensions(matrix_a) == (2, 2):
         return default_matrix_multiplication(matrix_a, matrix_b)
@@ -129,8 +129,8 @@ def strassen(matrix1: list, matrix2: list) -> list:
     new_matrix1 = matrix1
     new_matrix2 = matrix2
 
-    # Adding zeros to the matrices so that the arrays dimensions are the same and also
-    # power of 2
+    # Adding zeros to the matrices to convert them both into square matrices of equal
+    # dimensions that are a power of 2
     for i in range(maxim):
         if i < dimension1[0]:
             for _ in range(dimension1[1], maxim):