81. Find the length of a circular doubly linked list.
82. Search for an element in a circular doubly linked list.
83. Reverse a circular doubly linked list.
84. Split a circular doubly linked list into two halves.
85. Merge two circular doubly linked lists.
86. Convert a circular doubly linked list to a doubly linked list.
87. Remove duplicates from an unsorted doubly linked list.
88. Find the intersection point of two circular doubly linked lists.
89. Insert a node at a specific position in a circular doubly linked list.
90. Rotate a circular doubly linked list by k positions.
91. Find the middle element of a circular doubly linked list.
92. Swap two nodes in a circular doubly linked list.
93. Delete alternate nodes from a circular doubly linked list.
94. Pairwise swap elements in a circular doubly linked list.
95. Check if a circular doubly linked list is sorted.
96. Find the nth node from the end of a circular doubly linked list.
97. Convert a singly linked list to a circular doubly linked list.
98. Insert a node in a sorted circular doubly linked list.
99. Remove the last occurrence of an element from a circular doubly linked list.
100. Find if a circular doubly linked list is a palindrome.
101. Delete all nodes with a given value from a circular doubly linked list.
102. Move the last element to the front of a circular doubly linked list.
103. Find the maximum element in a circular doubly linked list.
104. Find the minimum element in a circular doubly linked list.
105. Clone a circular doubly linked list with random pointers.
106. Merge two sorted circular doubly linked lists.
107. Find the sum of all elements in a singly linked list.
108. Find the sum of all elements in a doubly linked list.
109. Find the sum of all elements in a circular linked list.
110. Find the sum of all elements in a circular doubly linked list.
111. Count occurrences of a given element in a singly linked list.
112. Count occurrences of a given element in a doubly linked list.
113. Count occurrences of a given element in a circular linked list.
114. Count occurrences of a given element in a circular doubly linked list.
115. Find the maximum difference between two nodes in a singly linked list.
116. Find the maximum difference between two nodes in a doubly linked list.
117. Find the maximum difference between two nodes in a circular linked list.
118. Find the maximum difference between two nodes in a circular doubly linked list.
119. Split a circular linked list into two circular lists.
120. Split a doubly linked list into two halves.