Clarify bitwise operations used in addition without arithmetic (#14059)

* Document addition function using bitwise operations

Added docstring explaining the bitwise addition method.

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* Refactor addition function documentation and output

Updated docstring to clarify the use of bitwise operations for addition. Modified the output format of the result to include both input values.

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Christian Clauss <cclauss@me.com>

Author: 3 people

maths/addition_without_arithmetic.py

@@ -8,7 +8,10 @@
 
 def add(first: int, second: int) -> int:
     """
-    Implementation of addition of integer
+    Add two integers using bitwise operations instead of arithmetic operators.
+    - XOR (^) to add bits without carrying
+    - AND (&) to calculate carry bits
+    - Left shift (<<) to move the carry to the correct position
 
     Examples:
     >>> add(3, 5)
@@ -19,10 +22,11 @@ def add(first: int, second: int) -> int:
     -5
     >>> add(0, -7)
     -7
-    >>> add(-321, 0)
-    -321
+    >>> add(-321, 1)
+    -320
     """
-    while second != 0:
+
+    while second != 0:  # Continue until there is no carry left
         c = first & second
         first ^= second
         second = c << 1
@@ -36,4 +40,4 @@ def add(first: int, second: int) -> int:
 
     first = int(input("Enter the first number: ").strip())
     second = int(input("Enter the second number: ").strip())
-    print(f"{add(first, second) = }")
+    print(f"{first = }, {second = }, {add(first, second) = }")