Added the Linked List Module to the Hackerrank Interview Prepration Kit with all 5 codes

Interview Preparation Kit - Python/Linked Lists/Find Merge Point of Two Lists.py

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+
+
+# Complete the findMergeNode function below.
+
+#
+# For your reference:
+#
+# SinglyLinkedListNode:
+#     int data
+#     SinglyLinkedListNode next
+#
+#
+def findMergeNode(head1, head2):
+    temp1=head1
+    temp2=head2
+    while(temp1!=temp2):
+        if(temp1.next==None):
+            temp1=head2
+        else:
+            temp1=temp1.next
+        if(temp2.next==None):
+            temp2=head1
+        else:
+            temp2=temp2.next
+    return temp2.data
+

Interview Preparation Kit - Python/Linked Lists/Insert_a_node_at_a_specific_position_in_a_linked_list.py

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+#!/bin/python3
+
+import math
+import os
+import random
+import re
+import sys
+
+class SinglyLinkedListNode:
+    def __init__(self, node_data):
+        self.data = node_data
+        self.next = None
+
+class SinglyLinkedList:
+    def __init__(self):
+        self.head = None
+        self.tail = None
+
+    def insert_node(self, node_data):
+        node = SinglyLinkedListNode(node_data)
+
+        if not self.head:
+            self.head = node
+        else:
+            self.tail.next = node
+
+
+        self.tail = node
+
+def print_singly_linked_list(node, sep, fptr):
+    while node:
+        fptr.write(str(node.data))
+
+        node = node.next
+
+        if node:
+            fptr.write(sep)
+
+# Complete the insertNodeAtPosition function below.
+
+#
+# For your reference:
+#
+# SinglyLinkedListNode:
+#     int data
+#     SinglyLinkedListNode next
+#
+#
+def insertNodeAtPosition(head, data, position):
+    counter=1
+    node1=SinglyLinkedListNode(data)
+    temp=head
+    while(counter!=position):
+        temp=temp.next
+        counter+=1
+    node1.next=temp.next
+    temp.next=node1
+    return head
+
+
+
+if __name__ == '__main__':

Interview Preparation Kit - Python/Linked Lists/Inserting a Node Into a Sorted Doubly Linked List.py

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+
+
+# Complete the sortedInsert function below.
+
+#
+# For your reference:
+#
+# DoublyLinkedListNode:
+#     int data
+#     DoublyLinkedListNode next
+#     DoublyLinkedListNode prev
+#
+#
+def sortedInsert(head, data):
+    prev=None
+    node1=DoublyLinkedListNode(data)
+    if(node1.data<head.data):
+        node1.next=head
+        head.previous=node1
+        head=node1
+        return head
+    temp=head.next
+    while(temp!=None):
+            if(temp.prev.data<=node1.data and node1.data<=temp.data):
+                break
+            else:
+                prev=temp
+                temp=temp.next
+    if(temp!=None):
+        node1.prev=temp.prev
+        node1.next=temp
+        temp.prev.next=node1
+        temp.prev=node1
+    else:
+        prev.next=node1
+        node1.prev=prev
+    return head
+
+

Interview Preparation Kit - Python/Linked Lists/Linked Lists: Detect a Cycle.py

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+"""
+Detect a cycle in a linked list. Note that the head pointer may be 'None' if the list is empty.
+
+A Node is defined as: 
+
+    class Node(object):
+        def __init__(self, data = None, next_node = None):
+            self.data = data
+            self.next = next_node
+"""
+
+
+def has_cycle(head):
+    temp=[]
+    travel=head
+    while(travel!=None):
+        if(travel in temp):
+            return True
+        else:
+            temp.append(travel)
+            travel=travel.next
+    return False
+

Interview Preparation Kit - Python/Linked Lists/Reverse a doubly linked list.py

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+
+
+# Complete the reverse function below.
+
+#
+# For your reference:
+#
+# DoublyLinkedListNode:
+#     int data
+#     DoublyLinkedListNode next
+#     DoublyLinkedListNode prev
+#
+#
+def reverse(head):
+    if(head==None or head.next==None):
+        return head
+    else:
+        temp=head
+        temp1=None
+        while temp is not None:  
+            temp1 = temp.prev;  
+            temp.prev = temp.next;  
+            temp.next = temp1;              
+            temp = temp.prev;    
+    head1=temp1.prev
+    return head1
+