Add is_even_using_shift_operator function

Introduces a new function to check if a number is even using bitwise shift operators. Includes docstring with explanation and doctest examples.

Author: ArunKishoreVoleti

bit_manipulation/is_even.py

@@ -30,6 +30,40 @@ def is_even(number: int) -> bool:
     """
     return number & 1 == 0
 
+def is_even_using_shift_operator(number: int) -> bool:
+    """
+    Returns True if the input integer is even.
+
+    Explanation:
+    In binary, even numbers end with 0, odd numbers end with 1.
+    Examples:
+    2  -> 10
+    3  -> 11
+    4  -> 100
+    5  -> 101
+
+    For odd numbers, the last bit is always 1.
+    Using shift:
+    (n >> 1) << 1 removes the last bit.
+    If result equals n, n is even.
+
+    >>> is_even_using_shift_operator(1)
+    False
+    >>> is_even_using_shift_operator(4)
+    True
+    >>> is_even_using_shift_operator(9)
+    False
+    >>> is_even_using_shift_operator(15)
+    False
+    >>> is_even_using_shift_operator(40)
+    True
+    >>> is_even_using_shift_operator(100)
+    True
+    >>> is_even_using_shift_operator(101)
+    False
+    """
+    return (number >> 1) << 1 == number
+
 
 if __name__ == "__main__":
     import doctest