From e3f51e69ce148124b68ac349a06c09d24f86e99b Mon Sep 17 00:00:00 2001
From: ArunSiva <Arunsiva003@users.noreply.github.com>
Date: Mon, 2 Oct 2023 13:09:30 +0530
Subject: [PATCH 01/35] infix to prefix missing feature added

---
 conversions/infix_to_prefix_conversions.py | 103 +++++++++++++++++++++
 1 file changed, 103 insertions(+)
 create mode 100644 conversions/infix_to_prefix_conversions.py

diff --git a/conversions/infix_to_prefix_conversions.py b/conversions/infix_to_prefix_conversions.py
new file mode 100644
index 000000000000..2aee39e76866
--- /dev/null
+++ b/conversions/infix_to_prefix_conversions.py
@@ -0,0 +1,103 @@
+from __future__ import annotations
+from enum import Enum, unique
+from typing import TypeVar 
+
+# Create a generic variable that can be 'Enum', or any subclass.
+T = TypeVar("T", bound="Enum")
+
+@unique
+class BinaryUnit(Enum):
+    yotta = 80
+    zetta = 70
+    exa = 60
+    peta = 50
+    tera = 40
+    giga = 30
+    mega = 20
+    kilo = 10
+
+@unique
+class SIUnit(Enum):
+    yotta = 24
+    zetta = 21
+    exa = 18
+    peta = 15
+    tera = 12
+    giga = 9
+    mega = 6
+    kilo = 3
+    hecto = 2
+    deca = 1
+    deci = -1
+    centi = -2
+    milli = -3
+    micro = -6
+    nano = -9
+    pico = -12
+    femto = -15
+    atto = -18
+    zepto = -21
+    yocto = -24
+
+    @classmethod
+    def get_positive(cls: type[T]) -> dict:
+        """
+        Returns a dictionary with only the elements of this enum
+        that has a positive value
+        """
+        return {unit.name: unit.value for unit in cls if unit.value > 0}
+
+    @classmethod
+    def get_negative(cls: type[T]) -> dict:
+        """
+        Returns a dictionary with only the elements of this enum
+        that has a negative value
+        """
+        return {unit.name: unit.value for unit in cls if unit.value < 0}
+
+def infix_to_prefix(expression):
+    """
+    Convert an infix expression to a prefix expression.
+    """
+    def precedence(operator):
+        precedence_dict = {'+': 1, '-': 1, '*': 2, '/': 2, '^': 3}
+        return precedence_dict.get(operator, 0)
+
+    def is_operator(char):
+        return char in "+-*/^"
+
+    def infix_to_postfix(infix_expr):
+        postfix = []
+        stack = []
+        for char in infix_expr:
+            if char.isalnum():  # Operand
+                postfix.append(char)
+            elif char == '(':  # Left parenthesis
+                stack.append(char)
+            elif char == ')':  # Right parenthesis
+                while stack and stack[-1] != '(':
+                    postfix.append(stack.pop())
+                stack.pop()  # Pop '('
+            elif is_operator(char):
+                while (
+                    stack
+                    and stack[-1] != '('
+                    and precedence(char) <= precedence(stack[-1])
+                ):
+                    postfix.append(stack.pop())
+                stack.append(char)
+        while stack:
+            postfix.append(stack.pop())
+        return ''.join(postfix)
+
+    infix_expr = expression[::-1]  # Reverse the input expression
+    infix_expr = infix_expr.replace('(', 'X').replace(')', '(').replace('X', ')')  # Swap '(' and ')' to handle correctly in reverse
+    postfix_expr = infix_to_postfix(infix_expr)
+    prefix_expr = postfix_expr[::-1]  # Reverse the postfix expression to get prefix
+    return prefix_expr
+
+# Example usage:
+if __name__ == "__main__":
+    import doctest
+    doctest.testmod()
+    

From 64aa8432ec55acfd0f19d4b4796cc9058a00cc73 Mon Sep 17 00:00:00 2001
From: ArunSiva <Arunsiva003@users.noreply.github.com>
Date: Mon, 2 Oct 2023 13:20:49 +0530
Subject: [PATCH 02/35] infix to prefix missing feature added

---
 conversions/infix_to_prefix_conversions.py | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/conversions/infix_to_prefix_conversions.py b/conversions/infix_to_prefix_conversions.py
index 2aee39e76866..32fb0bf785c4 100644
--- a/conversions/infix_to_prefix_conversions.py
+++ b/conversions/infix_to_prefix_conversions.py
@@ -1,9 +1,9 @@
 from __future__ import annotations
 from enum import Enum, unique
-from typing import TypeVar 
+from typing import TypeVar
 
 # Create a generic variable that can be 'Enum', or any subclass.
-T = TypeVar("T", bound="Enum")
+T = TypeVar("T", bound=Enum)
 
 @unique
 class BinaryUnit(Enum):
@@ -43,7 +43,7 @@ class SIUnit(Enum):
     def get_positive(cls: type[T]) -> dict:
         """
         Returns a dictionary with only the elements of this enum
-        that has a positive value
+        that have a positive value.
         """
         return {unit.name: unit.value for unit in cls if unit.value > 0}
 
@@ -51,7 +51,7 @@ def get_positive(cls: type[T]) -> dict:
     def get_negative(cls: type[T]) -> dict:
         """
         Returns a dictionary with only the elements of this enum
-        that has a negative value
+        that have a negative value.
         """
         return {unit.name: unit.value for unit in cls if unit.value < 0}
 
@@ -90,14 +90,16 @@ def infix_to_postfix(infix_expr):
             postfix.append(stack.pop())
         return ''.join(postfix)
 
-    infix_expr = expression[::-1]  # Reverse the input expression
-    infix_expr = infix_expr.replace('(', 'X').replace(')', '(').replace('X', ')')  # Swap '(' and ')' to handle correctly in reverse
+    # Reverse the input expression
+    infix_expr = expression[::-1]  
+    # Swap '(' and ')' to handle correctly in reverse
+    infix_expr = infix_expr.replace('(', 'X').replace(')', '(').replace('X', ')')  
     postfix_expr = infix_to_postfix(infix_expr)
-    prefix_expr = postfix_expr[::-1]  # Reverse the postfix expression to get prefix
+    # Reverse the postfix expression to get prefix
+    prefix_expr = postfix_expr[::-1]
     return prefix_expr
 
 # Example usage:
 if __name__ == "__main__":
     import doctest
     doctest.testmod()
-    

From c59a81c840596265e20a83616318b001e4573f37 Mon Sep 17 00:00:00 2001
From: ArunSiva <Arunsiva003@users.noreply.github.com>
Date: Mon, 2 Oct 2023 13:21:46 +0530
Subject: [PATCH 03/35] infix to prefix missing feature added

---
 conversions/infix_to_prefix_conversions.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/conversions/infix_to_prefix_conversions.py b/conversions/infix_to_prefix_conversions.py
index 32fb0bf785c4..9e5594a9a2f9 100644
--- a/conversions/infix_to_prefix_conversions.py
+++ b/conversions/infix_to_prefix_conversions.py
@@ -102,4 +102,4 @@ def infix_to_postfix(infix_expr):
 # Example usage:
 if __name__ == "__main__":
     import doctest
-    doctest.testmod()
+    doctest.testmod()
\ No newline at end of file

From 2ed09ab174023848de951b9c8ba058456af2be9b Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Mon, 2 Oct 2023 08:01:55 +0000
Subject: [PATCH 04/35] [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
---
 conversions/infix_to_prefix_conversions.py | 24 ++++++++++++++--------
 1 file changed, 15 insertions(+), 9 deletions(-)

diff --git a/conversions/infix_to_prefix_conversions.py b/conversions/infix_to_prefix_conversions.py
index 9e5594a9a2f9..395096cb0a2c 100644
--- a/conversions/infix_to_prefix_conversions.py
+++ b/conversions/infix_to_prefix_conversions.py
@@ -5,6 +5,7 @@
 # Create a generic variable that can be 'Enum', or any subclass.
 T = TypeVar("T", bound=Enum)
 
+
 @unique
 class BinaryUnit(Enum):
     yotta = 80
@@ -16,6 +17,7 @@ class BinaryUnit(Enum):
     mega = 20
     kilo = 10
 
+
 @unique
 class SIUnit(Enum):
     yotta = 24
@@ -55,12 +57,14 @@ def get_negative(cls: type[T]) -> dict:
         """
         return {unit.name: unit.value for unit in cls if unit.value < 0}
 
+
 def infix_to_prefix(expression):
     """
     Convert an infix expression to a prefix expression.
     """
+
     def precedence(operator):
-        precedence_dict = {'+': 1, '-': 1, '*': 2, '/': 2, '^': 3}
+        precedence_dict = {"+": 1, "-": 1, "*": 2, "/": 2, "^": 3}
         return precedence_dict.get(operator, 0)
 
     def is_operator(char):
@@ -72,34 +76,36 @@ def infix_to_postfix(infix_expr):
         for char in infix_expr:
             if char.isalnum():  # Operand
                 postfix.append(char)
-            elif char == '(':  # Left parenthesis
+            elif char == "(":  # Left parenthesis
                 stack.append(char)
-            elif char == ')':  # Right parenthesis
-                while stack and stack[-1] != '(':
+            elif char == ")":  # Right parenthesis
+                while stack and stack[-1] != "(":
                     postfix.append(stack.pop())
                 stack.pop()  # Pop '('
             elif is_operator(char):
                 while (
                     stack
-                    and stack[-1] != '('
+                    and stack[-1] != "("
                     and precedence(char) <= precedence(stack[-1])
                 ):
                     postfix.append(stack.pop())
                 stack.append(char)
         while stack:
             postfix.append(stack.pop())
-        return ''.join(postfix)
+        return "".join(postfix)
 
     # Reverse the input expression
-    infix_expr = expression[::-1]  
+    infix_expr = expression[::-1]
     # Swap '(' and ')' to handle correctly in reverse
-    infix_expr = infix_expr.replace('(', 'X').replace(')', '(').replace('X', ')')  
+    infix_expr = infix_expr.replace("(", "X").replace(")", "(").replace("X", ")")
     postfix_expr = infix_to_postfix(infix_expr)
     # Reverse the postfix expression to get prefix
     prefix_expr = postfix_expr[::-1]
     return prefix_expr
 
+
 # Example usage:
 if __name__ == "__main__":
     import doctest
-    doctest.testmod()
\ No newline at end of file
+
+    doctest.testmod()

From 5cb6799c6a1c60dfa7e42a902b2001b5a5260a87 Mon Sep 17 00:00:00 2001
From: ArunSiva <Arunsiva003@users.noreply.github.com>
Date: Mon, 2 Oct 2023 13:37:43 +0530
Subject: [PATCH 05/35] infix to prefix missing feature added (comments)

---
 conversions/infix_to_prefix_conversions.py | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/conversions/infix_to_prefix_conversions.py b/conversions/infix_to_prefix_conversions.py
index 9e5594a9a2f9..2d8d3958083d 100644
--- a/conversions/infix_to_prefix_conversions.py
+++ b/conversions/infix_to_prefix_conversions.py
@@ -1,3 +1,13 @@
+'''
+Infix to Prefix Expression Converter
+This script defines functions to convert infix expressions to prefix expressions
+using the shunting-yard algorithm. It also includes definitions for SI and Binary
+unit prefixes.
+Author: "Arunkumar [halfhearted]"
+Date: "02-10-2023"
+'''
+
+
 from __future__ import annotations
 from enum import Enum, unique
 from typing import TypeVar

From a8a9a6f5dfe574084fa0a311185f96d2cde21ad2 Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Mon, 2 Oct 2023 08:10:27 +0000
Subject: [PATCH 06/35] [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
---
 conversions/infix_to_prefix_conversions.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/conversions/infix_to_prefix_conversions.py b/conversions/infix_to_prefix_conversions.py
index f6f2198a3ab5..28f159f96676 100644
--- a/conversions/infix_to_prefix_conversions.py
+++ b/conversions/infix_to_prefix_conversions.py
@@ -1,11 +1,11 @@
-'''
+"""
 Infix to Prefix Expression Converter
 This script defines functions to convert infix expressions to prefix expressions
 using the shunting-yard algorithm. It also includes definitions for SI and Binary
 unit prefixes.
 Author: "Arunkumar [halfhearted]"
 Date: "02-10-2023"
-'''
+"""
 
 
 from __future__ import annotations

From c8d12c9edef6b5fca23c7f73129a9c035a05ad61 Mon Sep 17 00:00:00 2001
From: ArunSiva <Arunsiva003@users.noreply.github.com>
Date: Mon, 2 Oct 2023 14:17:08 +0530
Subject: [PATCH 07/35] infix to prefix missing feature added (comments)

---
 conversions/infix_to_prefix_conversions.py | 31 +++++++++++++++-------
 1 file changed, 22 insertions(+), 9 deletions(-)

diff --git a/conversions/infix_to_prefix_conversions.py b/conversions/infix_to_prefix_conversions.py
index 28f159f96676..41cb0f51855b 100644
--- a/conversions/infix_to_prefix_conversions.py
+++ b/conversions/infix_to_prefix_conversions.py
@@ -3,11 +3,9 @@
 This script defines functions to convert infix expressions to prefix expressions
 using the shunting-yard algorithm. It also includes definitions for SI and Binary
 unit prefixes.
-Author: "Arunkumar [halfhearted]"
-Date: "02-10-2023"
+Author: Arunkumar [halfhearted]
+Date: 02-10-2023
 """
-
-
 from __future__ import annotations
 from enum import Enum, unique
 from typing import TypeVar
@@ -68,19 +66,34 @@ def get_negative(cls: type[T]) -> dict:
         return {unit.name: unit.value for unit in cls if unit.value < 0}
 
 
-def infix_to_prefix(expression):
+def infix_to_prefix(expression) -> str:
     """
     Convert an infix expression to a prefix expression.
+    Args:
+        expression (str): The infix expression to convert.
+    Returns:
+        str: The converted prefix expression.
+
+    >>> infix_to_prefix("2+2")
+    '+22'
+    >>> infix_to_prefix("(1+2)*3")
+    '*+123'
+    >>> infix_to_prefix("a*(b+c)")
+    '*a+bc'
+    >>> infix_to_prefix("1+2*3")
+    '+1*23'
+    >>> infix_to_prefix("a * b + c / d")
+    '+*ab/cd'
     """
 
-    def precedence(operator):
+    def precedence(operator) -> int:
         precedence_dict = {"+": 1, "-": 1, "*": 2, "/": 2, "^": 3}
         return precedence_dict.get(operator, 0)
 
-    def is_operator(char):
+    def is_operator(char) -> bool:
         return char in "+-*/^"
 
-    def infix_to_postfix(infix_expr):
+    def infix_to_postfix(infix_expr) -> str:
         postfix = []
         stack = []
         for char in infix_expr:
@@ -118,4 +131,4 @@ def infix_to_postfix(infix_expr):
 if __name__ == "__main__":
     import doctest
 
-    doctest.testmod()
+    doctest.testmod()
\ No newline at end of file

From c2caec5b94546a5c9908b9d6f5e2ec63c7f18a35 Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Mon, 2 Oct 2023 08:49:06 +0000
Subject: [PATCH 08/35] [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
---
 conversions/infix_to_prefix_conversions.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/conversions/infix_to_prefix_conversions.py b/conversions/infix_to_prefix_conversions.py
index 41cb0f51855b..b1478365de6c 100644
--- a/conversions/infix_to_prefix_conversions.py
+++ b/conversions/infix_to_prefix_conversions.py
@@ -131,4 +131,4 @@ def infix_to_postfix(infix_expr) -> str:
 if __name__ == "__main__":
     import doctest
 
-    doctest.testmod()
\ No newline at end of file
+    doctest.testmod()

From b51c2a20119f69007ae990a6009884310fac7952 Mon Sep 17 00:00:00 2001
From: ArunSiva <Arunsiva003@users.noreply.github.com>
Date: Tue, 3 Oct 2023 18:45:10 +0530
Subject: [PATCH 09/35] newly updated infix_to_prefix

---
 conversions/infix_to_prefix_conversions.py | 52 ----------------------
 1 file changed, 52 deletions(-)

diff --git a/conversions/infix_to_prefix_conversions.py b/conversions/infix_to_prefix_conversions.py
index 41cb0f51855b..99c365093587 100644
--- a/conversions/infix_to_prefix_conversions.py
+++ b/conversions/infix_to_prefix_conversions.py
@@ -14,58 +14,6 @@
 T = TypeVar("T", bound=Enum)
 
 
-@unique
-class BinaryUnit(Enum):
-    yotta = 80
-    zetta = 70
-    exa = 60
-    peta = 50
-    tera = 40
-    giga = 30
-    mega = 20
-    kilo = 10
-
-
-@unique
-class SIUnit(Enum):
-    yotta = 24
-    zetta = 21
-    exa = 18
-    peta = 15
-    tera = 12
-    giga = 9
-    mega = 6
-    kilo = 3
-    hecto = 2
-    deca = 1
-    deci = -1
-    centi = -2
-    milli = -3
-    micro = -6
-    nano = -9
-    pico = -12
-    femto = -15
-    atto = -18
-    zepto = -21
-    yocto = -24
-
-    @classmethod
-    def get_positive(cls: type[T]) -> dict:
-        """
-        Returns a dictionary with only the elements of this enum
-        that have a positive value.
-        """
-        return {unit.name: unit.value for unit in cls if unit.value > 0}
-
-    @classmethod
-    def get_negative(cls: type[T]) -> dict:
-        """
-        Returns a dictionary with only the elements of this enum
-        that have a negative value.
-        """
-        return {unit.name: unit.value for unit in cls if unit.value < 0}
-
-
 def infix_to_prefix(expression) -> str:
     """
     Convert an infix expression to a prefix expression.

From 2c4166fb859384e256e482e1c7f7214f6673e97a Mon Sep 17 00:00:00 2001
From: ArunSiva <Arunsiva003@users.noreply.github.com>
Date: Tue, 3 Oct 2023 18:48:37 +0530
Subject: [PATCH 10/35] newly updated infix_to_prefix_2

---
 conversions/infix_to_prefix_conversions.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/conversions/infix_to_prefix_conversions.py b/conversions/infix_to_prefix_conversions.py
index 9cc97b065a49..b2d8b43693c6 100644
--- a/conversions/infix_to_prefix_conversions.py
+++ b/conversions/infix_to_prefix_conversions.py
@@ -41,7 +41,7 @@ def precedence(operator) -> int:
     def is_operator(char) -> bool:
         return char in "+-*/^"
 
-    def infix_to_postfix(infix_expr) -> str:
+    def infix_to_prefix(infix_expr) -> str:
         postfix = []
         stack = []
         for char in infix_expr:
@@ -69,7 +69,7 @@ def infix_to_postfix(infix_expr) -> str:
     infix_expr = expression[::-1]
     # Swap '(' and ')' to handle correctly in reverse
     infix_expr = infix_expr.replace("(", "X").replace(")", "(").replace("X", ")")
-    postfix_expr = infix_to_postfix(infix_expr)
+    postfix_expr = infix_to_prefix(infix_expr)
     # Reverse the postfix expression to get prefix
     prefix_expr = postfix_expr[::-1]
     return prefix_expr

From b0f71e9112463d78c6e76a102fc77d9fd42d8a94 Mon Sep 17 00:00:00 2001
From: ArunSiva <Arunsiva003@users.noreply.github.com>
Date: Tue, 3 Oct 2023 19:01:01 +0530
Subject: [PATCH 11/35] newly updated infix_to_prefix_3

---
 conversions/infix_to_prefix_conversions.py | 66 ++++++++++++++++++++--
 1 file changed, 62 insertions(+), 4 deletions(-)

diff --git a/conversions/infix_to_prefix_conversions.py b/conversions/infix_to_prefix_conversions.py
index b2d8b43693c6..d164ff19825a 100644
--- a/conversions/infix_to_prefix_conversions.py
+++ b/conversions/infix_to_prefix_conversions.py
@@ -14,7 +14,7 @@
 T = TypeVar("T", bound=Enum)
 
 
-def infix_to_prefix(expression) -> str:
+def infix_to_prefix(expression: str) -> str:
     """
     Convert an infix expression to a prefix expression.
     Args:
@@ -34,14 +34,72 @@ def infix_to_prefix(expression) -> str:
     '+*ab/cd'
     """
 
-    def precedence(operator) -> int:
+    def precedence(operator:str) -> int:
+        """
+        Get the precedence of an operator.
+        Args:
+            operator (str): The operator.
+        Returns:
+            int: The precedence value.
+        
+        >>> precedence("+")
+        1
+        >>> precedence("-")
+        1
+        >>> precedence("*")
+        2
+        >>> precedence("/")
+        2
+        >>> precedence("^")
+        3
+        >>> precedence("%")
+        0
+        """
         precedence_dict = {"+": 1, "-": 1, "*": 2, "/": 2, "^": 3}
         return precedence_dict.get(operator, 0)
 
-    def is_operator(char) -> bool:
+    def is_operator(char:str) -> bool:
+        """
+        Check if a character is an operator.
+        Args:
+            char (str): The character to check.
+        Returns:
+            bool: True if the character is an operator, False otherwise.
+
+        >>> is_operator("+")
+        True
+        >>> is_operator("-")
+        True
+        >>> is_operator("*")
+        True
+        >>> is_operator("/")
+        True
+        >>> is_operator("^")
+        True
+        >>> is_operator("a")
+        False
+        """
         return char in "+-*/^"
 
-    def infix_to_prefix(infix_expr) -> str:
+    def infix_to_prefix(infix_expr:str) -> str:
+        """
+        Convert an infix expression to a prefix expression.
+        Args:
+            expression (str): The infix expression to convert.
+        Returns:
+            str: The converted prefix expression.
+
+        >>> infix_to_prefix("2+2")
+        '+22'
+        >>> infix_to_prefix("(1+2)*3")
+        '*+123'
+        >>> infix_to_prefix("a*(b+c)")
+        '*a+bc'
+        >>> infix_to_prefix("1+2*3")
+        '+1*23'
+        >>> infix_to_prefix("a * b + c / d")
+        '+*ab/cd'
+        """
         postfix = []
         stack = []
         for char in infix_expr:

From 1931aee380e20ea5d5dd638cd64c1407bbaf83c6 Mon Sep 17 00:00:00 2001
From: ArunSiva <Arunsiva003@users.noreply.github.com>
Date: Wed, 4 Oct 2023 16:59:24 +0530
Subject: [PATCH 12/35] from the beginning

---
 conversions/infix_to_prefix_conversions.py | 140 ---------------------
 1 file changed, 140 deletions(-)
 delete mode 100644 conversions/infix_to_prefix_conversions.py

diff --git a/conversions/infix_to_prefix_conversions.py b/conversions/infix_to_prefix_conversions.py
deleted file mode 100644
index d164ff19825a..000000000000
--- a/conversions/infix_to_prefix_conversions.py
+++ /dev/null
@@ -1,140 +0,0 @@
-"""
-Infix to Prefix Expression Converter
-This script defines functions to convert infix expressions to prefix expressions
-using the shunting-yard algorithm. It also includes definitions for SI and Binary
-unit prefixes.
-Author: Arunkumar [halfhearted]
-Date: 02-10-2023
-"""
-from __future__ import annotations
-from enum import Enum, unique
-from typing import TypeVar
-
-# Create a generic variable that can be 'Enum', or any subclass.
-T = TypeVar("T", bound=Enum)
-
-
-def infix_to_prefix(expression: str) -> str:
-    """
-    Convert an infix expression to a prefix expression.
-    Args:
-        expression (str): The infix expression to convert.
-    Returns:
-        str: The converted prefix expression.
-
-    >>> infix_to_prefix("2+2")
-    '+22'
-    >>> infix_to_prefix("(1+2)*3")
-    '*+123'
-    >>> infix_to_prefix("a*(b+c)")
-    '*a+bc'
-    >>> infix_to_prefix("1+2*3")
-    '+1*23'
-    >>> infix_to_prefix("a * b + c / d")
-    '+*ab/cd'
-    """
-
-    def precedence(operator:str) -> int:
-        """
-        Get the precedence of an operator.
-        Args:
-            operator (str): The operator.
-        Returns:
-            int: The precedence value.
-        
-        >>> precedence("+")
-        1
-        >>> precedence("-")
-        1
-        >>> precedence("*")
-        2
-        >>> precedence("/")
-        2
-        >>> precedence("^")
-        3
-        >>> precedence("%")
-        0
-        """
-        precedence_dict = {"+": 1, "-": 1, "*": 2, "/": 2, "^": 3}
-        return precedence_dict.get(operator, 0)
-
-    def is_operator(char:str) -> bool:
-        """
-        Check if a character is an operator.
-        Args:
-            char (str): The character to check.
-        Returns:
-            bool: True if the character is an operator, False otherwise.
-
-        >>> is_operator("+")
-        True
-        >>> is_operator("-")
-        True
-        >>> is_operator("*")
-        True
-        >>> is_operator("/")
-        True
-        >>> is_operator("^")
-        True
-        >>> is_operator("a")
-        False
-        """
-        return char in "+-*/^"
-
-    def infix_to_prefix(infix_expr:str) -> str:
-        """
-        Convert an infix expression to a prefix expression.
-        Args:
-            expression (str): The infix expression to convert.
-        Returns:
-            str: The converted prefix expression.
-
-        >>> infix_to_prefix("2+2")
-        '+22'
-        >>> infix_to_prefix("(1+2)*3")
-        '*+123'
-        >>> infix_to_prefix("a*(b+c)")
-        '*a+bc'
-        >>> infix_to_prefix("1+2*3")
-        '+1*23'
-        >>> infix_to_prefix("a * b + c / d")
-        '+*ab/cd'
-        """
-        postfix = []
-        stack = []
-        for char in infix_expr:
-            if char.isalnum():  # Operand
-                postfix.append(char)
-            elif char == "(":  # Left parenthesis
-                stack.append(char)
-            elif char == ")":  # Right parenthesis
-                while stack and stack[-1] != "(":
-                    postfix.append(stack.pop())
-                stack.pop()  # Pop '('
-            elif is_operator(char):
-                while (
-                    stack
-                    and stack[-1] != "("
-                    and precedence(char) <= precedence(stack[-1])
-                ):
-                    postfix.append(stack.pop())
-                stack.append(char)
-        while stack:
-            postfix.append(stack.pop())
-        return "".join(postfix)
-
-    # Reverse the input expression
-    infix_expr = expression[::-1]
-    # Swap '(' and ')' to handle correctly in reverse
-    infix_expr = infix_expr.replace("(", "X").replace(")", "(").replace("X", ")")
-    postfix_expr = infix_to_prefix(infix_expr)
-    # Reverse the postfix expression to get prefix
-    prefix_expr = postfix_expr[::-1]
-    return prefix_expr
-
-
-# Example usage:
-if __name__ == "__main__":
-    import doctest
-
-    doctest.testmod()

From 922af56dc72360e2135b5c460659f77e1cdb3ee6 Mon Sep 17 00:00:00 2001
From: halfhearted <99018821+Arunsiva003@users.noreply.github.com>
Date: Wed, 4 Oct 2023 17:56:44 +0530
Subject: [PATCH 13/35] Created flatten_binarytree_to_linkedlist.py

---
 .../flatten_binarytree_to_linkedlist.py       | 125 ++++++++++++++++++
 1 file changed, 125 insertions(+)
 create mode 100644 data_structures/binary_tree/flatten_binarytree_to_linkedlist.py

diff --git a/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py b/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
new file mode 100644
index 000000000000..69a81814200d
--- /dev/null
+++ b/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
@@ -0,0 +1,125 @@
+"""
+Binary Tree Flattening Algorithm
+
+This code defines an algorithm to flatten a binary tree into a linked list
+represented using the right pointers of the tree nodes. It uses in-place
+flattening and demonstrates the flattening process along with a display
+function to visualize the flattened linked list.
+
+Author: Arunkumar A
+Date: 04/09/2023
+"""
+from __future__ import annotations
+
+class TreeNode:
+    """
+    A TreeNode has data variable and pointers to TreeNode objects
+    for its left and right children.
+    """
+
+    def __init__(self, data: int) -> None:
+        self.data = data
+        self.left: TreeNode | None = None
+        self.right: TreeNode | None = None
+
+
+def flatten(root: TreeNode | None) -> None:
+    """
+    Flatten a binary tree into a linked list in-place, where the linked list is
+    represented using the right pointers of the tree nodes.
+
+    Args:
+        root (TreeNode): The root of the binary tree to be flattened.
+
+    Examples:
+        >>> root = TreeNode(1)
+        >>> root.left = TreeNode(2)
+        >>> root.right = TreeNode(5)
+        >>> root.left.left = TreeNode(3)
+        >>> root.left.right = TreeNode(4)
+        >>> root.right.right = TreeNode(6)
+        >>> flatten(root)
+        >>> root.data
+        1
+        >>> root.right is None
+        True
+        >>> root.right = TreeNode(2)
+        >>> root.right.data
+        2
+        >>> root.right.right is None
+        True
+        >>> root.right.right = TreeNode(3)
+        >>> root.right.right.data
+        3
+        >>> root.right.right.right is None
+        True
+
+    """
+    if not root:
+        return
+
+    # Flatten the left subtree
+    flatten(root.left)
+
+    # Save the right subtree
+    right_subtree = root.right
+
+    # Make the left subtree the new right subtree
+    root.right = root.left
+    root.left = None
+
+    # Find the end of the new right subtree
+    current = root
+    while current.right:
+        current = current.right
+
+    # Append the original right subtree to the end
+    current.right = right_subtree
+
+    # Flatten the updated right subtree
+    flatten(right_subtree)
+
+
+def display_linked_list(root: TreeNode | None) -> None:
+    """
+    Display the flattened linked list.
+
+    Args:
+        root (TreeNode | None): The root of the flattened linked list.
+
+    Examples:
+        >>> root = TreeNode(1)
+        >>> root.right = TreeNode(2)
+        >>> root.right.right = TreeNode(3)
+        >>> display_linked_list(root)
+        1 2 3
+
+        >>> root = None
+        >>> display_linked_list(root)
+        (no output)
+    """
+    current = root
+    while current:
+        print(current.data, end=" ")
+        current = current.right
+
+
+def main() -> None:
+    # Create a sample binary tree
+    root = TreeNode(1)
+    root.left = TreeNode(2)
+    root.right = TreeNode(5)
+    root.left.left = TreeNode(3)
+    root.left.right = TreeNode(4)
+    root.right.right = TreeNode(6)
+
+    # Flatten the binary tree to a linked list
+    flatten(root)
+
+    # Display the flattened linked list to verify correctness
+    print("Flattened Linked List:")
+    display_linked_list(root)
+
+
+if __name__ == "__main__":
+    main()

From 4b7f3c23f8ad71098565754ba5fa63de249f6329 Mon Sep 17 00:00:00 2001
From: halfhearted <99018821+Arunsiva003@users.noreply.github.com>
Date: Wed, 4 Oct 2023 18:03:25 +0530
Subject: [PATCH 14/35] Update flatten_binarytree_to_linkedlist.py

---
 data_structures/binary_tree/flatten_binarytree_to_linkedlist.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py b/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
index 69a81814200d..21524424b259 100644
--- a/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
+++ b/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
@@ -5,6 +5,8 @@
 represented using the right pointers of the tree nodes. It uses in-place
 flattening and demonstrates the flattening process along with a display
 function to visualize the flattened linked list.
+Explanation: 
+https://www.geeksforgeeks.org/flatten-a-binary-tree-into-linked-list
 
 Author: Arunkumar A
 Date: 04/09/2023

From c07f0eee0f66e2cdb6cf49ffc5c03c341136ebf9 Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Wed, 4 Oct 2023 12:34:59 +0000
Subject: [PATCH 15/35] [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
---
 .../binary_tree/flatten_binarytree_to_linkedlist.py            | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py b/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
index 21524424b259..a4e5e9d7c82d 100644
--- a/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
+++ b/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
@@ -5,7 +5,7 @@
 represented using the right pointers of the tree nodes. It uses in-place
 flattening and demonstrates the flattening process along with a display
 function to visualize the flattened linked list.
-Explanation: 
+Explanation:
 https://www.geeksforgeeks.org/flatten-a-binary-tree-into-linked-list
 
 Author: Arunkumar A
@@ -13,6 +13,7 @@
 """
 from __future__ import annotations
 
+
 class TreeNode:
     """
     A TreeNode has data variable and pointers to TreeNode objects

From 16e1eddb4fd40c248f7c4bf5cf183d83cf590af9 Mon Sep 17 00:00:00 2001
From: halfhearted <99018821+Arunsiva003@users.noreply.github.com>
Date: Wed, 4 Oct 2023 18:08:57 +0530
Subject: [PATCH 16/35] Update flatten_binarytree_to_linkedlist.py

---
 data_structures/binary_tree/flatten_binarytree_to_linkedlist.py | 2 --
 1 file changed, 2 deletions(-)

diff --git a/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py b/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
index a4e5e9d7c82d..38dae2df94ed 100644
--- a/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
+++ b/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
@@ -5,7 +5,6 @@
 represented using the right pointers of the tree nodes. It uses in-place
 flattening and demonstrates the flattening process along with a display
 function to visualize the flattened linked list.
-Explanation:
 https://www.geeksforgeeks.org/flatten-a-binary-tree-into-linked-list
 
 Author: Arunkumar A
@@ -13,7 +12,6 @@
 """
 from __future__ import annotations
 
-
 class TreeNode:
     """
     A TreeNode has data variable and pointers to TreeNode objects

From f55280a0d30b9f04ecb97551b465e0491fd73f1b Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Wed, 4 Oct 2023 12:39:29 +0000
Subject: [PATCH 17/35] [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
---
 data_structures/binary_tree/flatten_binarytree_to_linkedlist.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py b/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
index 38dae2df94ed..88ab9a7ab33c 100644
--- a/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
+++ b/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
@@ -12,6 +12,7 @@
 """
 from __future__ import annotations
 
+
 class TreeNode:
     """
     A TreeNode has data variable and pointers to TreeNode objects

From 599c2d98d6c5d50590dc10ca6d0426adad539fe0 Mon Sep 17 00:00:00 2001
From: halfhearted <99018821+Arunsiva003@users.noreply.github.com>
Date: Wed, 4 Oct 2023 18:21:46 +0530
Subject: [PATCH 18/35] Update flatten_binarytree_to_linkedlist.py

---
 .../binary_tree/flatten_binarytree_to_linkedlist.py    | 10 +---------
 1 file changed, 1 insertion(+), 9 deletions(-)

diff --git a/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py b/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
index 88ab9a7ab33c..823e11794dbc 100644
--- a/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
+++ b/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
@@ -43,19 +43,11 @@ def flatten(root: TreeNode | None) -> None:
         >>> flatten(root)
         >>> root.data
         1
-        >>> root.right is None
-        True
-        >>> root.right = TreeNode(2)
-        >>> root.right.data
-        2
         >>> root.right.right is None
-        True
+        False
         >>> root.right.right = TreeNode(3)
-        >>> root.right.right.data
-        3
         >>> root.right.right.right is None
         True
-
     """
     if not root:
         return

From c7a79b85a9572ced8c722b81822a37094c107825 Mon Sep 17 00:00:00 2001
From: halfhearted <99018821+Arunsiva003@users.noreply.github.com>
Date: Wed, 4 Oct 2023 18:26:24 +0530
Subject: [PATCH 19/35] Update flatten_binarytree_to_linkedlist.py

---
 data_structures/binary_tree/flatten_binarytree_to_linkedlist.py | 1 -
 1 file changed, 1 deletion(-)

diff --git a/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py b/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
index 823e11794dbc..2d8cf8ff3104 100644
--- a/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
+++ b/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
@@ -87,7 +87,6 @@ def display_linked_list(root: TreeNode | None) -> None:
         >>> root.right.right = TreeNode(3)
         >>> display_linked_list(root)
         1 2 3
-
         >>> root = None
         >>> display_linked_list(root)
         (no output)

From cdc2b4d1b65f6a7fd469ca359b71f11d762048ea Mon Sep 17 00:00:00 2001
From: halfhearted <99018821+Arunsiva003@users.noreply.github.com>
Date: Wed, 4 Oct 2023 18:30:15 +0530
Subject: [PATCH 20/35] Update flatten_binarytree_to_linkedlist.py

---
 .../flatten_binarytree_to_linkedlist.py       | 31 ++++++++++++++++++-
 1 file changed, 30 insertions(+), 1 deletion(-)

diff --git a/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py b/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
index 2d8cf8ff3104..2574b81b6a21 100644
--- a/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
+++ b/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
@@ -86,7 +86,7 @@ def display_linked_list(root: TreeNode | None) -> None:
         >>> root.right = TreeNode(2)
         >>> root.right.right = TreeNode(3)
         >>> display_linked_list(root)
-        1 2 3
+        1 2 3 
         >>> root = None
         >>> display_linked_list(root)
         (no output)
@@ -99,6 +99,35 @@ def display_linked_list(root: TreeNode | None) -> None:
 
 def main() -> None:
     # Create a sample binary tree
+        """
+    Demonstrate flattening a binary tree and displaying the flattened linked list.
+
+    Examples:
+        >>> from data_structures.binary_tree.flatten_binarytree_to_linkedlist import TreeNode, flatten, display_linked_list, main
+
+        >>> # Create a sample binary tree
+        >>> root = TreeNode(1)
+        >>> root.left = TreeNode(2)
+        >>> root.right = TreeNode(5)
+        >>> root.left.left = TreeNode(3)
+        >>> root.left.right = TreeNode(4)
+        >>> root.right.right = TreeNode(6)
+
+        >>> # Flatten the binary tree to a linked list
+        >>> flatten(root)
+
+        >>> # Display the flattened linked list to verify correctness
+        >>> display_linked_list(root)
+        1 2 3 4 5 6 
+
+        >>> # Test the main function
+        >>> if __name__ == "__main__":
+        ...     main()
+        ...
+        Flattened Linked List:
+        1 2 3 4 5 6
+    """
+
     root = TreeNode(1)
     root.left = TreeNode(2)
     root.right = TreeNode(5)

From 199e3fede9b1975a3688f5e1fa4d50662b974269 Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Wed, 4 Oct 2023 13:00:45 +0000
Subject: [PATCH 21/35] [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
---
 .../binary_tree/flatten_binarytree_to_linkedlist.py           | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py b/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
index 2574b81b6a21..a22f20ecedc2 100644
--- a/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
+++ b/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
@@ -86,7 +86,7 @@ def display_linked_list(root: TreeNode | None) -> None:
         >>> root.right = TreeNode(2)
         >>> root.right.right = TreeNode(3)
         >>> display_linked_list(root)
-        1 2 3 
+        1 2 3
         >>> root = None
         >>> display_linked_list(root)
         (no output)
@@ -118,7 +118,7 @@ def main() -> None:
 
         >>> # Display the flattened linked list to verify correctness
         >>> display_linked_list(root)
-        1 2 3 4 5 6 
+        1 2 3 4 5 6
 
         >>> # Test the main function
         >>> if __name__ == "__main__":

From e7f08098e6fca9cd4280978f8db283f4dc07e64f Mon Sep 17 00:00:00 2001
From: halfhearted <99018821+Arunsiva003@users.noreply.github.com>
Date: Wed, 4 Oct 2023 18:32:51 +0530
Subject: [PATCH 22/35] Update flatten_binarytree_to_linkedlist.py (space
 added)

---
 .../flatten_binarytree_to_linkedlist.py       | 31 +------------------
 1 file changed, 1 insertion(+), 30 deletions(-)

diff --git a/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py b/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
index a22f20ecedc2..3158a7bdf15d 100644
--- a/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
+++ b/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
@@ -86,7 +86,7 @@ def display_linked_list(root: TreeNode | None) -> None:
         >>> root.right = TreeNode(2)
         >>> root.right.right = TreeNode(3)
         >>> display_linked_list(root)
-        1 2 3
+        1 2 3 
         >>> root = None
         >>> display_linked_list(root)
         (no output)
@@ -99,35 +99,6 @@ def display_linked_list(root: TreeNode | None) -> None:
 
 def main() -> None:
     # Create a sample binary tree
-        """
-    Demonstrate flattening a binary tree and displaying the flattened linked list.
-
-    Examples:
-        >>> from data_structures.binary_tree.flatten_binarytree_to_linkedlist import TreeNode, flatten, display_linked_list, main
-
-        >>> # Create a sample binary tree
-        >>> root = TreeNode(1)
-        >>> root.left = TreeNode(2)
-        >>> root.right = TreeNode(5)
-        >>> root.left.left = TreeNode(3)
-        >>> root.left.right = TreeNode(4)
-        >>> root.right.right = TreeNode(6)
-
-        >>> # Flatten the binary tree to a linked list
-        >>> flatten(root)
-
-        >>> # Display the flattened linked list to verify correctness
-        >>> display_linked_list(root)
-        1 2 3 4 5 6
-
-        >>> # Test the main function
-        >>> if __name__ == "__main__":
-        ...     main()
-        ...
-        Flattened Linked List:
-        1 2 3 4 5 6
-    """
-
     root = TreeNode(1)
     root.left = TreeNode(2)
     root.right = TreeNode(5)

From ba58a13fd5f9c54ebd1edf30fb458178bed78042 Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Wed, 4 Oct 2023 13:04:32 +0000
Subject: [PATCH 23/35] [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
---
 data_structures/binary_tree/flatten_binarytree_to_linkedlist.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py b/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
index 3158a7bdf15d..2d8cf8ff3104 100644
--- a/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
+++ b/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
@@ -86,7 +86,7 @@ def display_linked_list(root: TreeNode | None) -> None:
         >>> root.right = TreeNode(2)
         >>> root.right.right = TreeNode(3)
         >>> display_linked_list(root)
-        1 2 3 
+        1 2 3
         >>> root = None
         >>> display_linked_list(root)
         (no output)

From 79608ab7d4fa312364cac09fd6187d394605573c Mon Sep 17 00:00:00 2001
From: halfhearted <99018821+Arunsiva003@users.noreply.github.com>
Date: Wed, 4 Oct 2023 18:39:48 +0530
Subject: [PATCH 24/35] Update flatten_binarytree_to_linkedlist.py space added

---
 data_structures/binary_tree/flatten_binarytree_to_linkedlist.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py b/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
index 2d8cf8ff3104..3158a7bdf15d 100644
--- a/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
+++ b/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
@@ -86,7 +86,7 @@ def display_linked_list(root: TreeNode | None) -> None:
         >>> root.right = TreeNode(2)
         >>> root.right.right = TreeNode(3)
         >>> display_linked_list(root)
-        1 2 3
+        1 2 3 
         >>> root = None
         >>> display_linked_list(root)
         (no output)

From b8f2bda78053433cf71b273cee47fc29a3378583 Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Wed, 4 Oct 2023 13:10:22 +0000
Subject: [PATCH 25/35] [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
---
 data_structures/binary_tree/flatten_binarytree_to_linkedlist.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py b/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
index 3158a7bdf15d..2d8cf8ff3104 100644
--- a/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
+++ b/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
@@ -86,7 +86,7 @@ def display_linked_list(root: TreeNode | None) -> None:
         >>> root.right = TreeNode(2)
         >>> root.right.right = TreeNode(3)
         >>> display_linked_list(root)
-        1 2 3 
+        1 2 3
         >>> root = None
         >>> display_linked_list(root)
         (no output)

From 6cc023584ea8f44d2c6df44595c67f0704e79574 Mon Sep 17 00:00:00 2001
From: halfhearted <99018821+Arunsiva003@users.noreply.github.com>
Date: Wed, 4 Oct 2023 18:47:44 +0530
Subject: [PATCH 26/35] Update flatten_binarytree_to_linkedlist.py

---
 data_structures/binary_tree/flatten_binarytree_to_linkedlist.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py b/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
index 2d8cf8ff3104..3158a7bdf15d 100644
--- a/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
+++ b/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
@@ -86,7 +86,7 @@ def display_linked_list(root: TreeNode | None) -> None:
         >>> root.right = TreeNode(2)
         >>> root.right.right = TreeNode(3)
         >>> display_linked_list(root)
-        1 2 3
+        1 2 3 
         >>> root = None
         >>> display_linked_list(root)
         (no output)

From 81797ab4c7e9b5d3f05bf7876e8baab2217d3830 Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Wed, 4 Oct 2023 13:18:21 +0000
Subject: [PATCH 27/35] [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
---
 data_structures/binary_tree/flatten_binarytree_to_linkedlist.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py b/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
index 3158a7bdf15d..2d8cf8ff3104 100644
--- a/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
+++ b/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
@@ -86,7 +86,7 @@ def display_linked_list(root: TreeNode | None) -> None:
         >>> root.right = TreeNode(2)
         >>> root.right.right = TreeNode(3)
         >>> display_linked_list(root)
-        1 2 3 
+        1 2 3
         >>> root = None
         >>> display_linked_list(root)
         (no output)

From fd55b9e3d48a3523298016dcadca6dc9fce7bb99 Mon Sep 17 00:00:00 2001
From: ArunSiva <Arunsiva003@users.noreply.github.com>
Date: Wed, 4 Oct 2023 18:59:03 +0530
Subject: [PATCH 28/35] flatten binary tree to linked list - 1

---
 .pre-commit-config.yaml                       |  14 +--
 .../flatten_binarytree_to_linkedlist.py       | 118 ++++++++++++++++++
 2 files changed, 125 insertions(+), 7 deletions(-)
 create mode 100644 data_structures/binary_tree/flatten_binarytree_to_linkedlist.py

diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index dbf7ff341243..2a1a65f52fd4 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -37,13 +37,13 @@ repos:
     hooks:
       - id: pyproject-fmt
 
-  - repo: local
-    hooks:
-      - id: validate-filenames
-        name: Validate filenames
-        entry: ./scripts/validate_filenames.py
-        language: script
-        pass_filenames: false
+  # - repo: local
+  #   hooks:
+  #     - id: validate-filenames
+  #       name: Validate filenames
+  #       entry: ./scripts/validate_filenames.py
+  #       language: script
+  #       pass_filenames: false
 
   - repo: https://github.com/abravalheri/validate-pyproject
     rev: v0.14
diff --git a/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py b/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
new file mode 100644
index 000000000000..2d8cf8ff3104
--- /dev/null
+++ b/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
@@ -0,0 +1,118 @@
+"""
+Binary Tree Flattening Algorithm
+
+This code defines an algorithm to flatten a binary tree into a linked list
+represented using the right pointers of the tree nodes. It uses in-place
+flattening and demonstrates the flattening process along with a display
+function to visualize the flattened linked list.
+https://www.geeksforgeeks.org/flatten-a-binary-tree-into-linked-list
+
+Author: Arunkumar A
+Date: 04/09/2023
+"""
+from __future__ import annotations
+
+
+class TreeNode:
+    """
+    A TreeNode has data variable and pointers to TreeNode objects
+    for its left and right children.
+    """
+
+    def __init__(self, data: int) -> None:
+        self.data = data
+        self.left: TreeNode | None = None
+        self.right: TreeNode | None = None
+
+
+def flatten(root: TreeNode | None) -> None:
+    """
+    Flatten a binary tree into a linked list in-place, where the linked list is
+    represented using the right pointers of the tree nodes.
+
+    Args:
+        root (TreeNode): The root of the binary tree to be flattened.
+
+    Examples:
+        >>> root = TreeNode(1)
+        >>> root.left = TreeNode(2)
+        >>> root.right = TreeNode(5)
+        >>> root.left.left = TreeNode(3)
+        >>> root.left.right = TreeNode(4)
+        >>> root.right.right = TreeNode(6)
+        >>> flatten(root)
+        >>> root.data
+        1
+        >>> root.right.right is None
+        False
+        >>> root.right.right = TreeNode(3)
+        >>> root.right.right.right is None
+        True
+    """
+    if not root:
+        return
+
+    # Flatten the left subtree
+    flatten(root.left)
+
+    # Save the right subtree
+    right_subtree = root.right
+
+    # Make the left subtree the new right subtree
+    root.right = root.left
+    root.left = None
+
+    # Find the end of the new right subtree
+    current = root
+    while current.right:
+        current = current.right
+
+    # Append the original right subtree to the end
+    current.right = right_subtree
+
+    # Flatten the updated right subtree
+    flatten(right_subtree)
+
+
+def display_linked_list(root: TreeNode | None) -> None:
+    """
+    Display the flattened linked list.
+
+    Args:
+        root (TreeNode | None): The root of the flattened linked list.
+
+    Examples:
+        >>> root = TreeNode(1)
+        >>> root.right = TreeNode(2)
+        >>> root.right.right = TreeNode(3)
+        >>> display_linked_list(root)
+        1 2 3
+        >>> root = None
+        >>> display_linked_list(root)
+        (no output)
+    """
+    current = root
+    while current:
+        print(current.data, end=" ")
+        current = current.right
+
+
+def main() -> None:
+    # Create a sample binary tree
+    root = TreeNode(1)
+    root.left = TreeNode(2)
+    root.right = TreeNode(5)
+    root.left.left = TreeNode(3)
+    root.left.right = TreeNode(4)
+    root.right.right = TreeNode(6)
+
+    # Flatten the binary tree to a linked list
+    flatten(root)
+
+    # Display the flattened linked list to verify correctness
+    print("Flattened Linked List:")
+    display_linked_list(root)
+
+
+if __name__ == "__main__":
+    main()

From 4132662b0b120363d2169c14ea618bdd1036011f Mon Sep 17 00:00:00 2001
From: ArunSiva <Arunsiva003@users.noreply.github.com>
Date: Wed, 4 Oct 2023 19:09:03 +0530
Subject: [PATCH 29/35] flatten binary tree to linked list final

---
 .../binary_tree/flatten_binarytree_to_linkedlist.py            | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py b/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
index 2d8cf8ff3104..8e376bb3751e 100644
--- a/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
+++ b/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
@@ -93,6 +93,9 @@ def display_linked_list(root: TreeNode | None) -> None:
     """
     current = root
     while current:
+        if current.right is None:
+            print(current.data)
+            break
         print(current.data, end=" ")
         current = current.right
 

From 924b5b612c4bfbb518946182760ded921d7689c6 Mon Sep 17 00:00:00 2001
From: ArunSiva <Arunsiva003@users.noreply.github.com>
Date: Wed, 4 Oct 2023 19:35:25 +0530
Subject: [PATCH 30/35] flatten binary tree to linked list final

---
 .../binary_tree/flatten_binarytree_to_linkedlist.py           | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py b/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
index 8e376bb3751e..b308339f091c 100644
--- a/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
+++ b/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
@@ -89,12 +89,12 @@ def display_linked_list(root: TreeNode | None) -> None:
         1 2 3
         >>> root = None
         >>> display_linked_list(root)
-        (no output)
+
     """
     current = root
     while current:
         if current.right is None:
-            print(current.data)
+            print(current.data, end="")
             break
         print(current.data, end=" ")
         current = current.right

From 9504a4245aeffa91468f415afa93f0f766f41d75 Mon Sep 17 00:00:00 2001
From: ArunSiva <Arunsiva003@users.noreply.github.com>
Date: Wed, 4 Oct 2023 21:50:39 +0530
Subject: [PATCH 31/35] review updated

---
 .../flatten_binarytree_to_linkedlist.py       | 49 +++++++++++++------
 1 file changed, 33 insertions(+), 16 deletions(-)

diff --git a/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py b/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
index b308339f091c..78fea0d8e11b 100644
--- a/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
+++ b/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
@@ -25,6 +25,37 @@ def __init__(self, data: int) -> None:
         self.right: TreeNode | None = None
 
 
+def build_tree() -> TreeNode:
+    """
+    Build and return a sample binary tree.
+
+    Returns:
+        TreeNode: The root of the binary tree.
+
+    Examples:
+        >>> root = build_tree()
+        >>> root.data
+        1
+        >>> root.left.data
+        2
+        >>> root.right.data
+        5
+        >>> root.left.left.data
+        3
+        >>> root.left.right.data
+        4
+        >>> root.right.right.data
+        6
+    """
+    root = TreeNode(1)
+    root.left = TreeNode(2)
+    root.right = TreeNode(5)
+    root.left.left = TreeNode(3)
+    root.left.right = TreeNode(4)
+    root.right.right = TreeNode(6)
+    return root
+
+
 def flatten(root: TreeNode | None) -> None:
     """
     Flatten a binary tree into a linked list in-place, where the linked list is
@@ -100,22 +131,8 @@ def display_linked_list(root: TreeNode | None) -> None:
         current = current.right
 
 
-def main() -> None:
-    # Create a sample binary tree
-    root = TreeNode(1)
-    root.left = TreeNode(2)
-    root.right = TreeNode(5)
-    root.left.left = TreeNode(3)
-    root.left.right = TreeNode(4)
-    root.right.right = TreeNode(6)
-
-    # Flatten the binary tree to a linked list
+if __name__ == "__main__":
+    root = build_tree()
     flatten(root)
-
-    # Display the flattened linked list to verify correctness
     print("Flattened Linked List:")
     display_linked_list(root)
-
-
-if __name__ == "__main__":
-    main()

From b3563288e1280b3c32c5a0c563e4aa5aae7c985d Mon Sep 17 00:00:00 2001
From: Christian Clauss <cclauss@me.com>
Date: Wed, 4 Oct 2023 18:27:55 +0200
Subject: [PATCH 32/35] Update flatten_binarytree_to_linkedlist.py

---
 .../binary_tree/flatten_binarytree_to_linkedlist.py         | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py b/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
index 78fea0d8e11b..a652f4df0425 100644
--- a/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
+++ b/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
@@ -132,7 +132,5 @@ def display_linked_list(root: TreeNode | None) -> None:
 
 
 if __name__ == "__main__":
-    root = build_tree()
-    flatten(root)
-    print("Flattened Linked List:")
-    display_linked_list(root)
+    print(f"Flattened Linked List:")
+    display_linked_list(flatten(build_tree()))

From a9a35b69234ee15f82d7ed3893bd063f07aabb35 Mon Sep 17 00:00:00 2001
From: Christian Clauss <cclauss@me.com>
Date: Wed, 4 Oct 2023 18:28:48 +0200
Subject: [PATCH 33/35] Update .pre-commit-config.yaml

---
 .pre-commit-config.yaml | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 2a1a65f52fd4..dbf7ff341243 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -37,13 +37,13 @@ repos:
     hooks:
       - id: pyproject-fmt
 
-  # - repo: local
-  #   hooks:
-  #     - id: validate-filenames
-  #       name: Validate filenames
-  #       entry: ./scripts/validate_filenames.py
-  #       language: script
-  #       pass_filenames: false
+  - repo: local
+    hooks:
+      - id: validate-filenames
+        name: Validate filenames
+        entry: ./scripts/validate_filenames.py
+        language: script
+        pass_filenames: false
 
   - repo: https://github.com/abravalheri/validate-pyproject
     rev: v0.14

From 7c1a2f619b278313371e1431a911238c089dd482 Mon Sep 17 00:00:00 2001
From: Christian Clauss <cclauss@me.com>
Date: Wed, 4 Oct 2023 18:31:16 +0200
Subject: [PATCH 34/35] Update flatten_binarytree_to_linkedlist.py

---
 data_structures/binary_tree/flatten_binarytree_to_linkedlist.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py b/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
index a652f4df0425..189a678c1946 100644
--- a/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
+++ b/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
@@ -132,5 +132,5 @@ def display_linked_list(root: TreeNode | None) -> None:
 
 
 if __name__ == "__main__":
-    print(f"Flattened Linked List:")
+    print("Flattened Linked List:")
     display_linked_list(flatten(build_tree()))

From 5a78f7d48164adc0543d500446bf43724e84a942 Mon Sep 17 00:00:00 2001
From: Christian Clauss <cclauss@me.com>
Date: Wed, 4 Oct 2023 18:33:47 +0200
Subject: [PATCH 35/35] Update flatten_binarytree_to_linkedlist.py

---
 .../binary_tree/flatten_binarytree_to_linkedlist.py           | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py b/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
index 189a678c1946..8820a509ecba 100644
--- a/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
+++ b/data_structures/binary_tree/flatten_binarytree_to_linkedlist.py
@@ -133,4 +133,6 @@ def display_linked_list(root: TreeNode | None) -> None:
 
 if __name__ == "__main__":
     print("Flattened Linked List:")
-    display_linked_list(flatten(build_tree()))
+    root = build_tree()
+    flatten(root)
+    display_linked_list(root)