From cc63532964849e875bccfebaed41842a11b47935 Mon Sep 17 00:00:00 2001
From: Tapas Singhal <98687345+Shocker-lov-t@users.noreply.github.com>
Date: Sun, 29 Oct 2023 05:24:22 +0530
Subject: [PATCH 1/3] Create multiplexer.py

---
 boolean_algebra/multiplexer.py | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)
 create mode 100644 boolean_algebra/multiplexer.py

diff --git a/boolean_algebra/multiplexer.py b/boolean_algebra/multiplexer.py
new file mode 100644
index 000000000000..ec212e02b9a7
--- /dev/null
+++ b/boolean_algebra/multiplexer.py
@@ -0,0 +1,31 @@
+# https://www.electrically4u.com/solved-problems-on-multiplexer/
+
+def mux(input0: int, input1: int, select: int) -> int:
+    """
+    Implement a 2-to-1 Multiplexer.
+
+    :param input0: The first input value (0 or 1).
+    :param input1: The second input value (0 or 1).
+    :param select: The select signal (0 or 1) to choose between input0 and input1.
+    :return: The output based on the select signal.
+
+    >>> mux(0, 1, 0)
+    0
+    >>> mux(0, 1, 1)
+    1
+    >>> mux(1, 0, 0)
+    1
+    >>> mux(1, 0, 1)
+    0
+    """
+    if select == 0:
+        return input0
+    elif select == 1:
+        return input1
+    else:
+        raise ValueError("Select signal must be 0 or 1")
+
+if __name__ == "__main__":
+    import doctest
+
+    doctest.testmod()

From b86ef12dc19f8572b60d83b7de47f8f6614d80df Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Sat, 28 Oct 2023 23:56:02 +0000
Subject: [PATCH 2/3] [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
---
 boolean_algebra/multiplexer.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/boolean_algebra/multiplexer.py b/boolean_algebra/multiplexer.py
index ec212e02b9a7..abeb3f070f59 100644
--- a/boolean_algebra/multiplexer.py
+++ b/boolean_algebra/multiplexer.py
@@ -1,5 +1,6 @@
 # https://www.electrically4u.com/solved-problems-on-multiplexer/
 
+
 def mux(input0: int, input1: int, select: int) -> int:
     """
     Implement a 2-to-1 Multiplexer.
@@ -25,6 +26,7 @@ def mux(input0: int, input1: int, select: int) -> int:
     else:
         raise ValueError("Select signal must be 0 or 1")
 
+
 if __name__ == "__main__":
     import doctest
 

From 8c949124f5093b493ab7777fad4645f92e203431 Mon Sep 17 00:00:00 2001
From: Christian Clauss <cclauss@me.com>
Date: Sun, 29 Oct 2023 08:39:34 +0100
Subject: [PATCH 3/3] Doctests should show how the algorithm fails

---
 boolean_algebra/multiplexer.py | 29 +++++++++++++++++++----------
 1 file changed, 19 insertions(+), 10 deletions(-)

diff --git a/boolean_algebra/multiplexer.py b/boolean_algebra/multiplexer.py
index abeb3f070f59..7e65c785c829 100644
--- a/boolean_algebra/multiplexer.py
+++ b/boolean_algebra/multiplexer.py
@@ -1,6 +1,3 @@
-# https://www.electrically4u.com/solved-problems-on-multiplexer/
-
-
 def mux(input0: int, input1: int, select: int) -> int:
     """
     Implement a 2-to-1 Multiplexer.
@@ -8,7 +5,10 @@ def mux(input0: int, input1: int, select: int) -> int:
     :param input0: The first input value (0 or 1).
     :param input1: The second input value (0 or 1).
     :param select: The select signal (0 or 1) to choose between input0 and input1.
-    :return: The output based on the select signal.
+    :return: The output based on the select signal.  input1 if select else input0.
+
+    https://www.electrically4u.com/solved-problems-on-multiplexer
+    https://en.wikipedia.org/wiki/Multiplexer
 
     >>> mux(0, 1, 0)
     0
@@ -18,13 +18,22 @@ def mux(input0: int, input1: int, select: int) -> int:
     1
     >>> mux(1, 0, 1)
     0
+    >>> mux(2, 1, 0)
+    Traceback (most recent call last):
+        ...
+    ValueError: Inputs and select signal must be 0 or 1
+    >>> mux(0, -1, 0)
+    Traceback (most recent call last):
+        ...
+    ValueError: Inputs and select signal must be 0 or 1
+    >>> mux(0, 1, 1.1)
+    Traceback (most recent call last):
+        ...
+    ValueError: Inputs and select signal must be 0 or 1
     """
-    if select == 0:
-        return input0
-    elif select == 1:
-        return input1
-    else:
-        raise ValueError("Select signal must be 0 or 1")
+    if all(i in (0, 1) for i in (input0, input1, select)):
+        return input1 if select else input0
+    raise ValueError("Inputs and select signal must be 0 or 1")
 
 
 if __name__ == "__main__":