Merge aff6698fff into ad6395d340

* Update ruff usage example

* Update CONTRIBUTING.md

Co-authored-by: Tianyi Zheng <tianyizheng02@gmail.com>

---------

Co-authored-by: Tianyi Zheng <tianyizheng02@gmail.com>

CONTRIBUTING.md

@@ -96,7 +96,7 @@ We want your work to be readable by others; therefore, we encourage you to note
 
   ```bash
   python3 -m pip install ruff  # only required the first time
-  ruff .
+  ruff check
   ```
 
 - Original code submission require docstrings or comments to describe your work.

data_structures/stacks/lexicographical_numbers.py

@@ -0,0 +1,38 @@
+from collections.abc import Iterator
+
+
+def lexical_order(max_number: int) -> Iterator[int]:
+    """
+    Generate numbers in lexical order from 1 to max_number.
+
+    >>> " ".join(map(str, lexical_order(13)))
+    '1 10 11 12 13 2 3 4 5 6 7 8 9'
+    >>> list(lexical_order(1))
+    [1]
+    >>> " ".join(map(str, lexical_order(20)))
+    '1 10 11 12 13 14 15 16 17 18 19 2 20 3 4 5 6 7 8 9'
+    >>> " ".join(map(str, lexical_order(25)))
+    '1 10 11 12 13 14 15 16 17 18 19 2 20 21 22 23 24 25 3 4 5 6 7 8 9'
+    >>> list(lexical_order(12))
+    [1, 10, 11, 12, 2, 3, 4, 5, 6, 7, 8, 9]
+    """
+
+    stack = [1]
+
+    while stack:
+        num = stack.pop()
+        if num > max_number:
+            continue
+
+        yield num
+        if (num % 10) != 9:
+            stack.append(num + 1)
+
+        stack.append(num * 10)
+
+
+if __name__ == "__main__":
+    from doctest import testmod
+
+    testmod()
+    print(f"Numbers from 1 to 25 in lexical order: {list(lexical_order(26))}")

dynamic_programming/longest_common_subsequence.py

@@ -28,6 +28,24 @@ def longest_common_subsequence(x: str, y: str):
     (2, 'ph')
     >>> longest_common_subsequence("computer", "food")
     (1, 'o')
+    >>> longest_common_subsequence("", "abc")  # One string is empty
+    (0, '')
+    >>> longest_common_subsequence("abc", "")  # Other string is empty
+    (0, '')
+    >>> longest_common_subsequence("", "")  # Both strings are empty
+    (0, '')
+    >>> longest_common_subsequence("abc", "def")  # No common subsequence
+    (0, '')
+    >>> longest_common_subsequence("abc", "abc")  # Identical strings
+    (3, 'abc')
+    >>> longest_common_subsequence("a", "a")  # Single character match
+    (1, 'a')
+    >>> longest_common_subsequence("a", "b")  # Single character no match
+    (0, '')
+    >>> longest_common_subsequence("abcdef", "ace")  # Interleaved subsequence
+    (3, 'ace')
+    >>> longest_common_subsequence("ABCD", "ACBD")  # No repeated characters
+    (3, 'ABD')
     """
     # find the length of strings
 

physics/bragg_angle.py

@@ -0,0 +1,41 @@
+import math
+
+
+def bragg_angle(distance: float, order: int, wavelength: float) -> float:
+    """
+    Calculate the Bragg diffraction angle using the formula:
+    sin(θ) = (n * λ) / (2 * d)
+
+    Parameters:
+    distance d (float): Distance between crystal planes (in meters).
+    order n (int): Order of reflection.
+    wavelength λ (float): Wavelength of the radiation (in meters).
+
+    Examples:
+    >>> bragg_angle(2.2e-10, 1, 2.2e-10)
+    30.0
+
+    >>> bragg_angle(5e-10, 2, 1e-10)
+    11.5
+
+    >>> bragg_angle(4e-10, 1, 4e-10)
+    30.0
+
+    # Test case for an invalid sine value (out of range)
+    >>> bragg_angle(1e-10, 2, 3e-10)
+    Traceback (most recent call last):
+        ...
+    ValueError: The calculated sine value is out of the valid range.
+    """
+    sine_theta = (order * wavelength) / (2 * distance)
+    if sine_theta > 1 or sine_theta < -1:
+        raise ValueError("The calculated sine value is out of the valid range.")
+    theta_radians = math.asin(sine_theta)
+    theta_degrees = math.degrees(theta_radians)
+    return round(theta_degrees, 1)
+
+
+if __name__ == "__main__":
+    import doctest
+
+    doctest.testmod(verbose=True)