advanced linked lists referencesheadtailand probelisting provides an implementation for searching sorted doubly linked list using the probing technique listing probing doubly linked list given the headtailand probe referencesprobe the list for target make sure the list is not empty if head is none return false if probe is nullinitialize it to the first node elif probe is none probe head if the target comes before the probe nodewe traverse backwardotherwise traverse forward if target probe data while probe is not none and target <probe data if target =probe data return true else probe probe prev else while probe is not none and target >probe data if target =probe data return true else probe probe next if the target is not found in the listreturn false return false as with singly linked listall of the list operations must also work with an empty listindicated by null head reference with the probe operationthe search simply fails if the list is empty this can be quickly determined by examining the head reference the probe reference can also be null at the beginning of the search operation this can occur when the first search is performedsince the probe reference has not been positioned within the list by previous search operation we could manage probe within the insert and deletion operations and make adjustments each time new node is added or deleted but performing this check within the search operation is just as easyespecially since this is the only operation in which probe is utilized the probe reference can also become null when the previous search fails after the traversal has exhausted all possible nodes and the external reference "falls off the list but unlike with null head referencethe search does not necessarily fail insteadthe probe reference must be initialized to point to the first node in the list to prepare for the current search the actual search is performed by either traversing forward or backward depending on the relation between the target and the key value in the node referenced by probe if the target is smaller than probe' keythen reverse sorted list traver