From 99dc0fb0cfc666e5e5d724d755385831ef1fdb92 Mon Sep 17 00:00:00 2001
From: Sajied Shah Yousuf <40203390+meSajied@users.noreply.github.com>
Date: Tue, 31 Mar 2020 19:43:49 +0600
Subject: [PATCH 01/13] Added new Algorithm to find middle element of Linked
 List

---
 .../linked_list/MiddleElementOfLinkedList.py  | 42 +++++++++++++++++++
 1 file changed, 42 insertions(+)
 create mode 100644 data_structures/linked_list/MiddleElementOfLinkedList.py

diff --git a/data_structures/linked_list/MiddleElementOfLinkedList.py b/data_structures/linked_list/MiddleElementOfLinkedList.py
new file mode 100644
index 000000000000..2a006e474122
--- /dev/null
+++ b/data_structures/linked_list/MiddleElementOfLinkedList.py
@@ -0,0 +1,42 @@
+# From Google Find the middle element of a linked list.....
+
+#Node Setup
+class Node:
+
+    def __init__(self, data, next):
+
+        self.data = data
+        self.next = next
+
+# setup some nodes and connect them to each other
+# the linked list looks like:
+# (head) n5 -> n4 -> n3 -> n2 -> n1 -> None
+
+if __name__ == "__main__":
+    node1 = Node("hello", None)
+    node2 = Node("Deniel", node1)
+    node3 = Node("Blue", node2)
+    node4 = Node("Green", node3)
+    node5 = Node("Me", node4)
+
+    # assign a node to the head which functions
+    # as the entry into our linked list
+
+    head = node5
+
+    # setup pointers to both start
+    # at the head of the linked list
+
+    fastPointer = head
+    slowPointer = head
+
+    # loop through the linked list
+    # when fastPointer reaches the end of the list
+    # then slowPointer will be at the middle node
+
+    while fastPointer.next != None and fastPointer.next.next != None:
+        fastPointer = fastPointer.next.next
+        slowPointer = slowPointer.next
+
+    # slowPointer is now at the middle node in the linked list
+    print(slowPointer.data)

From 3cecfa639037371daa86e8a63d94db43f095a6f8 Mon Sep 17 00:00:00 2001
From: Sajied Shah Yousuf <40203390+meSajied@users.noreply.github.com>
Date: Wed, 1 Apr 2020 10:41:24 +0600
Subject: [PATCH 02/13] Rename MiddleElementOfLinkedList.py to
 middle_element_of_linked_list.py

---
 ...dleElementOfLinkedList.py => middle_element_of_linked_list.py} | 0
 1 file changed, 0 insertions(+), 0 deletions(-)
 rename data_structures/linked_list/{MiddleElementOfLinkedList.py => middle_element_of_linked_list.py} (100%)

diff --git a/data_structures/linked_list/MiddleElementOfLinkedList.py b/data_structures/linked_list/middle_element_of_linked_list.py
similarity index 100%
rename from data_structures/linked_list/MiddleElementOfLinkedList.py
rename to data_structures/linked_list/middle_element_of_linked_list.py

From 3057ed73f64d6e73d703fdf13d03b68f565e67d3 Mon Sep 17 00:00:00 2001
From: Sajied Shah Yousuf <40203390+meSajied@users.noreply.github.com>
Date: Thu, 9 Apr 2020 17:05:28 +0600
Subject: [PATCH 03/13] changed "middle_element_of_linked_list.py" algorithm
 for taking input

---
 .../middle_element_of_linked_list.py          | 64 +++++++------------
 1 file changed, 23 insertions(+), 41 deletions(-)

diff --git a/data_structures/linked_list/middle_element_of_linked_list.py b/data_structures/linked_list/middle_element_of_linked_list.py
index 2a006e474122..5e4e6d1e945b 100644
--- a/data_structures/linked_list/middle_element_of_linked_list.py
+++ b/data_structures/linked_list/middle_element_of_linked_list.py
@@ -1,42 +1,24 @@
-# From Google Find the middle element of a linked list.....
-
-#Node Setup
 class Node:
-
-    def __init__(self, data, next):
-
-        self.data = data
-        self.next = next
-
-# setup some nodes and connect them to each other
-# the linked list looks like:
-# (head) n5 -> n4 -> n3 -> n2 -> n1 -> None
-
-if __name__ == "__main__":
-    node1 = Node("hello", None)
-    node2 = Node("Deniel", node1)
-    node3 = Node("Blue", node2)
-    node4 = Node("Green", node3)
-    node5 = Node("Me", node4)
-
-    # assign a node to the head which functions
-    # as the entry into our linked list
-
-    head = node5
-
-    # setup pointers to both start
-    # at the head of the linked list
-
-    fastPointer = head
-    slowPointer = head
-
-    # loop through the linked list
-    # when fastPointer reaches the end of the list
-    # then slowPointer will be at the middle node
-
-    while fastPointer.next != None and fastPointer.next.next != None:
-        fastPointer = fastPointer.next.next
-        slowPointer = slowPointer.next
-
-    # slowPointer is now at the middle node in the linked list
-    print(slowPointer.data)
+    def __init__(self, data):  
+        self.data = data  
+        self.next = None 
+
+class LinkedList: 
+    def __init__(self): 
+        self.head = None
+
+    def push(self, new_data): 
+        new_node = Node(new_data) 
+        new_node.next = self.head 
+        self.head = new_node
+
+    def middle_element(self):
+        slow_pointer = self.head
+        fast_pointer = self.head
+
+        if self.head is not None: 
+            while (fast_pointer is not None and fast_pointer.next is not None): 
+                fast_pointer = fast_pointer.next.next
+                slow_pointer = slow_pointer.next
+            
+            return slow_pointer.data

From ae6358ced0c7082451a872d0b069e28d0ca0a3d9 Mon Sep 17 00:00:00 2001
From: Sajied Shah Yousuf <40203390+meSajied@users.noreply.github.com>
Date: Thu, 9 Apr 2020 17:16:23 +0600
Subject: [PATCH 04/13] Update middle_element_of_linked_list.py

---
 .../linked_list/middle_element_of_linked_list.py         | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/data_structures/linked_list/middle_element_of_linked_list.py b/data_structures/linked_list/middle_element_of_linked_list.py
index 5e4e6d1e945b..bbfa261b6ac8 100644
--- a/data_structures/linked_list/middle_element_of_linked_list.py
+++ b/data_structures/linked_list/middle_element_of_linked_list.py
@@ -22,3 +22,12 @@ def middle_element(self):
                 slow_pointer = slow_pointer.next
             
             return slow_pointer.data
+
+if __name__ == "__main__":
+    link = LinkedList()
+    N = int(input())
+
+    for i in range(N):
+        data = int(input())
+        link.push(data)
+    print(link.middle_element())

From f2b41111f550f634de38ec21d58c18fa41fd46bc Mon Sep 17 00:00:00 2001
From: Sajied Shah Yousuf <40203390+meSajied@users.noreply.github.com>
Date: Thu, 9 Apr 2020 20:53:35 +0600
Subject: [PATCH 05/13] Update middle_element_of_linked_list.py

---
 .../linked_list/middle_element_of_linked_list.py       | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/data_structures/linked_list/middle_element_of_linked_list.py b/data_structures/linked_list/middle_element_of_linked_list.py
index bbfa261b6ac8..3b0a8f9bd557 100644
--- a/data_structures/linked_list/middle_element_of_linked_list.py
+++ b/data_structures/linked_list/middle_element_of_linked_list.py
@@ -1,5 +1,5 @@
 class Node:
-    def __init__(self, data):  
+    def __init__(self, data:int) -> int:  
         self.data = data  
         self.next = None 
 
@@ -7,12 +7,12 @@ class LinkedList:
     def __init__(self): 
         self.head = None
 
-    def push(self, new_data): 
+    def push(self, new_data:int) -> int: 
         new_node = Node(new_data) 
         new_node.next = self.head 
         self.head = new_node
 
-    def middle_element(self):
+    def middle_element(self) -> int:
         slow_pointer = self.head
         fast_pointer = self.head
 
@@ -25,9 +25,9 @@ def middle_element(self):
 
 if __name__ == "__main__":
     link = LinkedList()
-    N = int(input())
+    N = int(input().strip())
 
     for i in range(N):
-        data = int(input())
+        data = int(input().strip())
         link.push(data)
     print(link.middle_element())

From 4675d7fbc294878bef64803b61032927f7309448 Mon Sep 17 00:00:00 2001
From: Sajied Shah Yousuf <40203390+meSajied@users.noreply.github.com>
Date: Sat, 11 Apr 2020 20:14:51 +0600
Subject: [PATCH 06/13] Update middle_element_of_linked_list.py

---
 .../middle_element_of_linked_list.py          | 22 +++++++++++++++----
 1 file changed, 18 insertions(+), 4 deletions(-)

diff --git a/data_structures/linked_list/middle_element_of_linked_list.py b/data_structures/linked_list/middle_element_of_linked_list.py
index 3b0a8f9bd557..fe46c6807c4f 100644
--- a/data_structures/linked_list/middle_element_of_linked_list.py
+++ b/data_structures/linked_list/middle_element_of_linked_list.py
@@ -3,16 +3,31 @@ def __init__(self, data:int) -> int:
         self.data = data  
         self.next = None 
 
-class LinkedList: 
+class LinkedList:
+    '''
+    >>> link = LinkedList()
+    '''
+
     def __init__(self): 
         self.head = None
 
-    def push(self, new_data:int) -> int: 
+    def push(self, new_data:int) -> int:
+        '''
+        >>> link.push(4)
+        >>> link.push(3)
+        >>> link.push(8)
+        >>> link.push(7)
+        >>> link.push(9)
+        >>> link.push(11)
+        '''
         new_node = Node(new_data) 
         new_node.next = self.head 
         self.head = new_node
 
     def middle_element(self) -> int:
+        '''
+        >>> link.middle_element()
+        '''
         slow_pointer = self.head
         fast_pointer = self.head
 
@@ -23,10 +38,9 @@ def middle_element(self) -> int:
             
             return slow_pointer.data
 
-if __name__ == "__main__":
+if __name__ == "__main__":   
     link = LinkedList()
     N = int(input().strip())
-
     for i in range(N):
         data = int(input().strip())
         link.push(data)

From 5dbf5aa8336de2bdf63076df3797acbe9184b652 Mon Sep 17 00:00:00 2001
From: Sajied Shah Yousuf <40203390+meSajied@users.noreply.github.com>
Date: Sat, 11 Apr 2020 20:33:44 +0600
Subject: [PATCH 07/13] Update middle_element_of_linked_list.py

---
 .../middle_element_of_linked_list.py          | 28 ++++++++-----------
 1 file changed, 12 insertions(+), 16 deletions(-)

diff --git a/data_structures/linked_list/middle_element_of_linked_list.py b/data_structures/linked_list/middle_element_of_linked_list.py
index fe46c6807c4f..04635eea9bde 100644
--- a/data_structures/linked_list/middle_element_of_linked_list.py
+++ b/data_structures/linked_list/middle_element_of_linked_list.py
@@ -4,30 +4,15 @@ def __init__(self, data:int) -> int:
         self.next = None 
 
 class LinkedList:
-    '''
-    >>> link = LinkedList()
-    '''
-
     def __init__(self): 
         self.head = None
 
     def push(self, new_data:int) -> int:
-        '''
-        >>> link.push(4)
-        >>> link.push(3)
-        >>> link.push(8)
-        >>> link.push(7)
-        >>> link.push(9)
-        >>> link.push(11)
-        '''
         new_node = Node(new_data) 
         new_node.next = self.head 
         self.head = new_node
 
     def middle_element(self) -> int:
-        '''
-        >>> link.middle_element()
-        '''
         slow_pointer = self.head
         fast_pointer = self.head
 
@@ -38,9 +23,20 @@ def middle_element(self) -> int:
             
             return slow_pointer.data
 
-if __name__ == "__main__":   
+if __name__ == "__main__":
+    '''
+    >>> link = LinkedList()
+    >>> link.push(4)
+    >>> link.push(3)
+    >>> link.push(8)
+    >>> link.push(7)
+    >>> link.push(9)
+    >>> link.push(11)
+    >>> link.middle_element()
+    '''
     link = LinkedList()
     N = int(input().strip())
+
     for i in range(N):
         data = int(input().strip())
         link.push(data)

From 9a2adedab1a7629a8f9ce548803de9a14a07e11a Mon Sep 17 00:00:00 2001
From: Sajied Shah Yousuf <40203390+meSajied@users.noreply.github.com>
Date: Sat, 11 Apr 2020 20:48:27 +0600
Subject: [PATCH 08/13] Update middle_element_of_linked_list.py

---
 .../middle_element_of_linked_list.py          | 20 +++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/data_structures/linked_list/middle_element_of_linked_list.py b/data_structures/linked_list/middle_element_of_linked_list.py
index 04635eea9bde..d597ed7f5211 100644
--- a/data_structures/linked_list/middle_element_of_linked_list.py
+++ b/data_structures/linked_list/middle_element_of_linked_list.py
@@ -13,6 +13,16 @@ def push(self, new_data:int) -> int:
         self.head = new_node
 
     def middle_element(self) -> int:
+        '''
+        >>> link = LinkedList()
+        >>> link.push(4)
+        >>> link.push(3)
+        >>> link.push(8)
+        >>> link.push(7)
+        >>> link.push(9)
+        >>> link.push(11)
+        >>> link.middle_element()
+        '''
         slow_pointer = self.head
         fast_pointer = self.head
 
@@ -24,16 +34,6 @@ def middle_element(self) -> int:
             return slow_pointer.data
 
 if __name__ == "__main__":
-    '''
-    >>> link = LinkedList()
-    >>> link.push(4)
-    >>> link.push(3)
-    >>> link.push(8)
-    >>> link.push(7)
-    >>> link.push(9)
-    >>> link.push(11)
-    >>> link.middle_element()
-    '''
     link = LinkedList()
     N = int(input().strip())
 

From 8f553881e3910e1c9aae6a5c28d25fbfcc621abc Mon Sep 17 00:00:00 2001
From: Sajied Shah Yousuf <40203390+meSajied@users.noreply.github.com>
Date: Sat, 11 Apr 2020 20:53:30 +0600
Subject: [PATCH 09/13] Update middle_element_of_linked_list.py

---
 .../linked_list/middle_element_of_linked_list.py            | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/data_structures/linked_list/middle_element_of_linked_list.py b/data_structures/linked_list/middle_element_of_linked_list.py
index d597ed7f5211..253117def37c 100644
--- a/data_structures/linked_list/middle_element_of_linked_list.py
+++ b/data_structures/linked_list/middle_element_of_linked_list.py
@@ -16,11 +16,17 @@ def middle_element(self) -> int:
         '''
         >>> link = LinkedList()
         >>> link.push(4)
+        4
         >>> link.push(3)
+        3
         >>> link.push(8)
+        8
         >>> link.push(7)
+        7
         >>> link.push(9)
+        9
         >>> link.push(11)
+        11
         >>> link.middle_element()
         '''
         slow_pointer = self.head

From 8432de611f704b380a45eebe386ef5b85c561bc8 Mon Sep 17 00:00:00 2001
From: Sajied Shah Yousuf <40203390+meSajied@users.noreply.github.com>
Date: Sun, 12 Apr 2020 15:57:22 +0600
Subject: [PATCH 10/13] Update middle_element_of_linked_list.py

---
 .../middle_element_of_linked_list.py          | 31 ++++++++++++-------
 1 file changed, 19 insertions(+), 12 deletions(-)

diff --git a/data_structures/linked_list/middle_element_of_linked_list.py b/data_structures/linked_list/middle_element_of_linked_list.py
index 253117def37c..5b386ae36752 100644
--- a/data_structures/linked_list/middle_element_of_linked_list.py
+++ b/data_structures/linked_list/middle_element_of_linked_list.py
@@ -1,7 +1,7 @@
 class Node:
     def __init__(self, data:int) -> int:  
         self.data = data  
-        self.next = None 
+        self.next = None
 
 class LinkedList:
     def __init__(self): 
@@ -11,34 +11,41 @@ def push(self, new_data:int) -> int:
         new_node = Node(new_data) 
         new_node.next = self.head 
         self.head = new_node
+        return self.head.data
 
     def middle_element(self) -> int:
         '''
         >>> link = LinkedList()
-        >>> link.push(4)
-        4
-        >>> link.push(3)
-        3
+        >>> link.push(5)
+        5
+        >>> link.push(6)
+        6
         >>> link.push(8)
         8
+        >>> link.push(8)
+        8
+        >>> link.push(10)
+        10
+        >>> link.push(12)
+        12
+        >>> link.push(17)
+        17
         >>> link.push(7)
         7
-        >>> link.push(9)
-        9
-        >>> link.push(11)
-        11
+        >>> link.push(3)
+        3
         >>> link.middle_element()
+        10
+        >>> 
         '''
         slow_pointer = self.head
         fast_pointer = self.head
-
         if self.head is not None: 
             while (fast_pointer is not None and fast_pointer.next is not None): 
                 fast_pointer = fast_pointer.next.next
                 slow_pointer = slow_pointer.next
-            
             return slow_pointer.data
-
+            
 if __name__ == "__main__":
     link = LinkedList()
     N = int(input().strip())

From ddfe1d163d7310e85474f1e3d2d3cd2c706b1a62 Mon Sep 17 00:00:00 2001
From: Sajied Shah Yousuf <40203390+meSajied@users.noreply.github.com>
Date: Sun, 12 Apr 2020 19:03:45 +0600
Subject: [PATCH 11/13] Update middle_element_of_linked_list.py

---
 .../linked_list/middle_element_of_linked_list.py            | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/data_structures/linked_list/middle_element_of_linked_list.py b/data_structures/linked_list/middle_element_of_linked_list.py
index 5b386ae36752..6bb4fd8140ec 100644
--- a/data_structures/linked_list/middle_element_of_linked_list.py
+++ b/data_structures/linked_list/middle_element_of_linked_list.py
@@ -34,8 +34,12 @@ def middle_element(self) -> int:
         7
         >>> link.push(3)
         3
+        >>> link.push(20)
+        20
+        >>> link.push(-20)
+        -20
         >>> link.middle_element()
-        10
+        12
         >>> 
         '''
         slow_pointer = self.head

From 5b7af7a3ccc955b64df83e81ef4eb064f6f7e3db Mon Sep 17 00:00:00 2001
From: Sajied Shah Yousuf <40203390+meSajied@users.noreply.github.com>
Date: Sun, 12 Apr 2020 20:22:05 +0600
Subject: [PATCH 12/13] Update middle_element_of_linked_list.py

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

diff --git a/data_structures/linked_list/middle_element_of_linked_list.py b/data_structures/linked_list/middle_element_of_linked_list.py
index 6bb4fd8140ec..647bc77f2c3d 100644
--- a/data_structures/linked_list/middle_element_of_linked_list.py
+++ b/data_structures/linked_list/middle_element_of_linked_list.py
@@ -6,16 +6,16 @@ def __init__(self, data:int) -> int:
 class LinkedList:
     def __init__(self): 
         self.head = None
-
     def push(self, new_data:int) -> int:
         new_node = Node(new_data) 
         new_node.next = self.head 
         self.head = new_node
         return self.head.data
-
     def middle_element(self) -> int:
         '''
         >>> link = LinkedList()
+        >>> link.middle_element()
+        No element found.
         >>> link.push(5)
         5
         >>> link.push(6)
@@ -49,6 +49,8 @@ def middle_element(self) -> int:
                 fast_pointer = fast_pointer.next.next
                 slow_pointer = slow_pointer.next
             return slow_pointer.data
+        else:
+            print("No element found.")
             
 if __name__ == "__main__":
     link = LinkedList()

From b80618dab47bdfb847712eafcdcf4995b2035c45 Mon Sep 17 00:00:00 2001
From: Christian Clauss <cclauss@me.com>
Date: Sun, 12 Apr 2020 16:36:25 +0200
Subject: [PATCH 13/13] Whack the trailing whitespace

---
 .../middle_element_of_linked_list.py          | 20 ++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/data_structures/linked_list/middle_element_of_linked_list.py b/data_structures/linked_list/middle_element_of_linked_list.py
index 647bc77f2c3d..2903fe604dfa 100644
--- a/data_structures/linked_list/middle_element_of_linked_list.py
+++ b/data_structures/linked_list/middle_element_of_linked_list.py
@@ -1,16 +1,19 @@
 class Node:
-    def __init__(self, data:int) -> int:  
-        self.data = data  
+    def __init__(self, data: int) -> int:
+        self.data = data
         self.next = None
 
+
 class LinkedList:
-    def __init__(self): 
+    def __init__(self):
         self.head = None
+
     def push(self, new_data:int) -> int:
         new_node = Node(new_data) 
         new_node.next = self.head 
         self.head = new_node
         return self.head.data
+
     def middle_element(self) -> int:
         '''
         >>> link = LinkedList()
@@ -44,19 +47,18 @@ def middle_element(self) -> int:
         '''
         slow_pointer = self.head
         fast_pointer = self.head
-        if self.head is not None: 
-            while (fast_pointer is not None and fast_pointer.next is not None): 
+        if self.head: 
+            while fast_pointer and fast_pointer.next: 
                 fast_pointer = fast_pointer.next.next
                 slow_pointer = slow_pointer.next
             return slow_pointer.data
         else:
             print("No element found.")
-            
+
+
 if __name__ == "__main__":
     link = LinkedList()
-    N = int(input().strip())
-
-    for i in range(N):
+    for i in range(int(input().strip())):
         data = int(input().strip())
         link.push(data)
     print(link.middle_element())