How to Delete all occurrences of a given key in a doubly linked list

[Question]: Given a doubly linked list and a key x. The problem is to delete all occurrences of the given key x from the doubly linked list.

#Approach: we declare two variable prevNode and nxtNode and in a loop if we finds the data value of linklist node is equals to k just break link to the node.

func deleteOccuranceInLinkedList(_ k: Int, _ list: DoublyLinkedListNode<Int>?) -> DoublyLinkedListNode<Int>? {
    var tempCopy = list
    while tempCopy != nil {
        var prevNode = tempCopy?.previous
        var nxtNode = tempCopy?.next

        if tempCopy?.item == k {
            prevNode?.next = nxtNode
            nxtNode?.previous = prevNode
        tempCopy = tempCopy?.next
    return tempCopy

var occuranceLinkedList = DoublyLinkedList<Int>()
occuranceLinkedList  = [1,2,3,2,1,4,5]
deleteOccuranceInLinkedList(2, occuranceLinkedList.head)
//print(" after deleting k linked list is", occuranceLinkedList)// 1,3,1,4,5

Leave a Comment

Your email address will not be published. Required fields are marked *