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authorMattias Andrée <maandree@operamail.com>2014-01-22 10:58:17 +0100
committerMattias Andrée <maandree@operamail.com>2014-01-22 10:58:17 +0100
commit94633a4fcb3d86ffe7dd77087fc317ccf2c694cd (patch)
treeef4c331a6f101da40e064a0ddc4bc2548d3a13b8
parentadd topological sort (diff)
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add singly linked list
Signed-off-by: Mattias Andrée <maandree@operamail.com>
-rw-r--r--src/datastructures/linkedlists/SinglyLinkedList.java160
1 files changed, 160 insertions, 0 deletions
diff --git a/src/datastructures/linkedlists/SinglyLinkedList.java b/src/datastructures/linkedlists/SinglyLinkedList.java
new file mode 100644
index 0000000..137736c
--- /dev/null
+++ b/src/datastructures/linkedlists/SinglyLinkedList.java
@@ -0,0 +1,160 @@
+/**
+ * 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 <http://www.gnu.org/licenses/>.
+ */
+package datastructures.linkedlists;
+
+
+/**
+ * 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
+ * two refence nodes, the first node in the list,
+ * and the last node in the list. The 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 <T> The value stored in the structure
+ */
+public class SinglyLinkedList<T>
+{
+ /**
+ * Node for the list
+ */
+ public class Node
+ {
+ /**
+ * Constructor
+ *
+ * @param value The value to store in the list
+ */
+ private Node(T value)
+ {
+ this.value = value;
+ }
+
+
+
+ /**
+ * The value stored in the list by this node
+ */
+ public T value;
+
+ /**
+ * The next node in the list
+ */
+ public Node next = null;
+
+ }
+
+
+
+ /**
+ * The first node in the list
+ */
+ public Node head = null;
+
+ /**
+ * The last node in the list
+ */
+ public Node tail = null;
+
+
+
+ /**
+ * Insert a value in the beginning of the list
+ *
+ * @param value The value to insert
+ * @return The node that has be created and inserted
+ */
+ public Node insertBeginning(T value)
+ {
+ Node node = new Node(value);
+ node.next = this.head;
+ if (this.head == null)
+ this.tail = node;
+ this.head = node;
+ return node;
+ }
+
+ /**
+ * Remove the node at the beginning of the list
+ *
+ * @return The node that has been removed
+ */
+ public Node removeBeginning()
+ {
+ Node node = head;
+ if (node != null)
+ head = head.next;
+ if (this.tail == node)
+ this.tail = null;
+ return node;
+ }
+
+ /**
+ * Insert a value after a specified, reference, node
+ *
+ * @param value The value to insert
+ * @param predecessor The reference node
+ * @return The node that has be created and inserted
+ */
+ public Node insertAfter(T value, Node predecessor)
+ {
+ Node node = new Node(value);
+ node.next = predecessor.next;
+ predecessor.next = node;
+ if (this.tail == predecessor)
+ this.tail = node;
+ return node;
+ }
+
+ /**
+ * Remove the node after a specified, reference, node
+ *
+ * @param predecessor The reference node
+ * @return The node that has been removed
+ */
+ public Node removeAfter(Node predecessor)
+ {
+ Node node = predecessor.next;
+ if (node == null)
+ predecessor.next = node.next;
+ if (this.tail == node)
+ this.tail = predecessor;
+ return node;
+ }
+
+ /**
+ * Insert a value in the end of the list
+ *
+ * @param value The value to insert
+ * @return The node that has be created and inserted
+ */
+ public Node insertEnd(T value)
+ {
+ if (this.tail == null)
+ return insertBeginning(value);
+ return insertAfter(value, this.tail);
+ }
+
+}
+