From d14587d925df5c54c1cbde35bac0ba830eb9f82e Mon Sep 17 00:00:00 2001
From: urvesh254 <urveshpatel2001@gmail.com>
Date: Sat, 16 Oct 2021 01:30:50 +0530
Subject: [PATCH] Algorithm for reversing the linkedlist using efficient manner
 in Python.

---
 ReverseLinkedList.py | 57 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)
 create mode 100644 ReverseLinkedList.py

diff --git a/ReverseLinkedList.py b/ReverseLinkedList.py
new file mode 100644
index 0000000..627f512
--- /dev/null
+++ b/ReverseLinkedList.py
@@ -0,0 +1,57 @@
+"""
+    Author: Urveshkumar Patel
+    GitHub: https://github.com/urvesh254
+"""
+
+
+class Node:
+    """It is a representation of the LinkedList node."""
+
+    def __init__(self, data, next=None) -> None:
+        self.data = data
+        self.next = next
+
+
+def reverseLL(head) -> Node:
+    """
+    Efficient method for reversing the LinkedList.
+
+    Time Complexity: O(n)
+    Space Complexity: O(1)
+
+    @param head Start pointer of the LinkedList.
+    @return Updated head after reversing the LinkedList.
+    """
+
+    pre, curr, next = None, head, None
+    while curr:
+        pre = curr.next
+        curr.next = next
+        next = curr
+
+        curr = pre
+
+    return next
+
+
+""" Uncomment below code for Testing """
+
+"""
+def displayLL(head):
+    q = head
+    while q:
+        print(q.data, end="->")
+        q = q.next
+    print()
+
+
+head = Node("1")
+head.next = Node("2")
+head.next.next = Node("3")
+head.next.next.next = Node("4")
+head.next.next.next.next = Node("5")
+head.next.next.next.next.next = Node("6")
+
+displayLL(head)
+displayLL(reverseLL(head))
+"""