Doubly-linked list/Definition: Difference between revisions
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=={{header|JavaScript}}== |
=={{header|JavaScript}}== |
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See [[Doubly-Linked List (element)#JavaScript]], [[Doubly-Linked List (element insertion)#JavaScript]] and [[Doubly-Linked List (traversal)#JavaScript]] |
See [[Doubly-Linked List (element)#JavaScript]], [[Doubly-Linked List (element insertion)#JavaScript]] and [[Doubly-Linked List (traversal)#JavaScript]] |
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=={{header|Kotlin}}== |
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Rather than use the java.util.LinkedList<E> class, we will write our own simple LinkedList<E> class for this task: |
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<lang scala>// version 1.1.1 |
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class LinkedList<E> { |
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class Node<E>(var data: E, var prev: Node<E>? = null, var next: Node<E>? = null) { |
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override fun toString(): String { |
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val sb = StringBuilder(this.data.toString()) |
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var node = this.next |
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while (node != null) { |
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sb.append(" -> ", node.data.toString()) |
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node = node.next |
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} |
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return sb.toString() |
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} |
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} |
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var first: Node<E>? = null |
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var last: Node<E>? = null |
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fun addFirst(value: E) { |
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if (first == null) { |
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first = Node(value) |
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last = first |
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} |
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else { |
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val node = first!! |
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first = Node(value, null, node) |
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node.prev = first |
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} |
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} |
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fun addLast(value: E) { |
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if (last == null) { |
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last = Node(value) |
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first = last |
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} |
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else { |
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val node = last!! |
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last = Node(value, node, null) |
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node.next = last |
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} |
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} |
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fun insert(after: Node<E>?, value: E) { |
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if (after == null) |
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addFirst(value) |
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else if (after == last) |
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addLast(value) |
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else { |
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val next = after.next |
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val new = Node(value, after, next) |
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after.next = new |
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if (next != null) next.prev = new |
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} |
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} |
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override fun toString() = first.toString() |
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} |
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fun main(args: Array<String>) { |
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val ll = LinkedList<Int>() |
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ll.addFirst(1) |
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ll.addLast(4) |
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ll.insert(ll.first, 2) |
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ll.insert(ll.last!!.prev, 3) |
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println(ll) |
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}</lang> |
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{{out}} |
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<pre> |
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1 -> 2 -> 3 -> 4 |
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</pre> |
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=={{header|Nim}}== |
=={{header|Nim}}== |
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