From 564354ad8ef2044e68f5a26b155bfe0f4c9397c2 Mon Sep 17 00:00:00 2001 From: Mattias Andrée Date: Wed, 22 Jan 2014 12:36:23 +0100 Subject: add headless linked lists MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Mattias Andrée --- .../linkedlists/HeadlessDoublyLinkedList.java | 40 ++++++++++++++++++ .../linkedlists/HeadlessSinglyLinkedList.java | 49 ++++++++++++++++++++++ src/datastructures/linkedlists/template | 5 ++- 3 files changed, 93 insertions(+), 1 deletion(-) create mode 100644 src/datastructures/linkedlists/HeadlessDoublyLinkedList.java create mode 100644 src/datastructures/linkedlists/HeadlessSinglyLinkedList.java (limited to 'src/datastructures/linkedlists') diff --git a/src/datastructures/linkedlists/HeadlessDoublyLinkedList.java b/src/datastructures/linkedlists/HeadlessDoublyLinkedList.java new file mode 100644 index 0000000..23a59f1 --- /dev/null +++ b/src/datastructures/linkedlists/HeadlessDoublyLinkedList.java @@ -0,0 +1,40 @@ +/** + * Copyright © 2014 Mattias Andrée (maandree@member.fsf.org) + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU Affero General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU Affero General Public License for more details. + * + * You should have received a copy of the GNU Affero General Public License + * along with this program. If not, see . + */ +package datastructures.linkedlists; + + +/** + * Headless doubly linked list class. A linked list + * is a list constructed from nodes, which hold stored + * values, with references to each other, this is + * usally an ineffective data structure, especially + * on high-level object orientated languages. A + * doublely linked list stores nodes with references + * to both the following node and the previous node. + * It also stores one refence nodes, the last node + * in the list. This implemention only implements + * methods that do not require iterating over all + * nodes for find a specific; all other methods' — + * those that are * implemented — time complexity + * is Θ(1). + * + * @param The value stored in the structure + */ +public class HeadlessDoublyLinkedList +£>export with_head=0 with_tail=1 with_prev=1 +£>gpp -s £ < src/datastructures/linkedlists/template | sed -e '/^[/ ]\*/d' + diff --git a/src/datastructures/linkedlists/HeadlessSinglyLinkedList.java b/src/datastructures/linkedlists/HeadlessSinglyLinkedList.java new file mode 100644 index 0000000..4bbff31 --- /dev/null +++ b/src/datastructures/linkedlists/HeadlessSinglyLinkedList.java @@ -0,0 +1,49 @@ +/** + * Copyright © 2014 Mattias Andrée (maandree@member.fsf.org) + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU Affero General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU Affero General Public License for more details. + * + * You should have received a copy of the GNU Affero General Public License + * along with this program. If not, see . + */ +package datastructures.linkedlists; + + +/** + * Headless singly linked list class. A linked list + * is a list constructed from nodes, which hold + * stored values, with references to each other, + * this is usally an ineffective data structure, + * especially on high-level object orientated + * languages. A singly linked list only stores nodes + * with references to the following node. It also + * stores one refence nodes, the last node in the + * list. This implemention only implements methods + * that do not require iterating over all nodes for + * find a specific; all other methods' — those that + * are implemented — time complexity is Θ(1). + * + * A headless singly linked list some features that + * could be an advantage depending on what you are + * using it for: Because it is singly linked it uses + * slightly less memory and it is slightly faster. + * Because it is also headless there is not need to + * remove nodes from the beginning of the list if you + * are iterating over the list, they are automatically + * lost and freed by the garbage collector (assuming + * there is one.) + * + * @param The value stored in the structure + */ +public class HeadlessSinglyLinkedList +£>export with_head=0 with_tail=1 with_prev=0 +£>gpp -s £ < src/datastructures/linkedlists/template | sed -e '/^[/ ]\*/d' + diff --git a/src/datastructures/linkedlists/template b/src/datastructures/linkedlists/template index 0a24a89..71c6a84 100644 --- a/src/datastructures/linkedlists/template +++ b/src/datastructures/linkedlists/template @@ -193,7 +193,7 @@ node.next = successor; if (node.previous != null) node.previous.next = node; -£>if (( with_tail )); then +£>if (( with_head )); then if (this.head == successor) this.head = node; £>fi @@ -252,7 +252,10 @@ public Node insertEnd(T value) { if (this.tail == null) +£>(( with_head )) && return insertBeginning(value); +£>(( with_head )) || + return this.tail = new Node(value); return insertAfter(value, this.tail); } -- cgit v1.2.3-70-g09d2