skip list Algorithm

fast search is made possible by keeping a associated hierarchy of subsequences, with each successive subsequence skipping over fewer components than the previous one (see the picture below on the right).Searching starts in the sparsest subsequence until two consecutive components have been found, one smaller and one larger than or equal to the component searched for. Skip lists are a probabilistic data structure that seem likely to supplant balanced trees as the implementation method of choice for many applications. Skip list algorithms have the same asymptotic expected time boundary as balanced trees and are simpler, faster and use less space. To quote the writer:

skip list source code, pseudocode and analysis