Searching Algorithms Questions Medium
A skip list is a data structure that allows for efficient searching, insertion, and deletion operations in a sorted list of elements. It is similar to a linked list, but with additional layers of linked lists called "levels" that allow for faster traversal and search.
In a skip list, each element is represented by a node that contains a key and a set of forward pointers. The forward pointers point to the next node with a key greater than or equal to the current node's key. The bottom level of the skip list is a regular linked list that contains all the elements in sorted order.
The key feature of a skip list is the use of multiple levels. Each level is created by randomly determining whether a node at the current level should have a forward pointer to the next level. This randomization process creates a "skipping" effect, where some nodes have forward pointers that allow for faster traversal across multiple levels.
By using this skipping effect, the skip list achieves an average time complexity of O(log n) for search, insertion, and deletion operations, where n is the number of elements in the list. This is comparable to other efficient searching algorithms like binary search trees and balanced search trees, but skip lists have the advantage of being simpler to implement and requiring less memory overhead.
Overall, a skip list is a versatile data structure that provides efficient searching capabilities while maintaining a relatively simple design. It is commonly used in scenarios where fast search operations are required, such as in database indexing or in implementing ordered sets and maps.