Add is_even_using_shift_operator function

bit_manipulation/is_even.py

@@ -31,6 +31,41 @@ 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