Adding Simple Solution for Problem - 206 - Reverse Linked List

Author: Vanditg

Reverse_LinkedList/SimpleSolution.py

@@ -0,0 +1,43 @@
+##==================================
+## Leetcode
+## Student: Vandit Jyotindra Gajjar
+## Year: 2020
+## Problem: 206
+## Problem Name: Reverse Linked List
+##===================================
+#
+#Reverse a singly linked list.
+#
+#Example:
+#
+#Input: 1->2->3->4->5->NULL
+#Output: 5->4->3->2->1->NULL
+class Solution:
+    def reverseList(self, head):
+        previous = None    #Set previous to None
+        current = head     #Set current to head 
+        while current:     #While our head is not empty
+            following = current.next    #Our following points to current.next
+            current.next = previous     #Current.next will be previous 
+            previous = current          #Our previous points to current
+            current = following    #Current points to following
+        head = previous     #Set head to previous
+        return head     #We'll return head at the end.
+#Example 
+#Input: head = [1, 2]
+#previous = None
+#current = [1, 2]
+#While Loop:
+#current = [1, 2]
+#following = [2]
+#current next = None (Null)
+#previous =  [1]
+#current = [2]
+#--------------
+#current = [2]
+#following = None (Null)
+#current next = [1]
+#previous =  [2, 1]
+#current = None (Null)
+---------------
+#head = [2, 1]