Implementation of Singly Linked List in Java.

SinglyLinkedList.java

/**
 * @file
 *  Singly linked list.
 */

public class SinglyLinkedList {

	public int key;

	public SinglyLinkedList next;


	/**
	 *
	 */
	public SinglyLinkedList get_last(SinglyLinkedList begin) {

		if (begin == null) return null;

		SinglyLinkedList p = begin;

		while(p.next != null) p = p.next;

		return p;
	}


	public SinglyLinkedList get_by_key(SinglyLinkedList begin, int key) {

		if (begin == null) return null;

		SinglyLinkedList p = begin;

		while(p != null) {

			if (p.key == key) return p;

			p = p.next;
		}

		return null;
	}

	// i vale de 1 até infinito.
	public SinglyLinkedList get_nesim(SinglyLinkedList begin, int i) {

		if (begin == null) return null;

		SinglyLinkedList p = begin;

		int n = 1;

		while((p != null) && (n < i)) {

			p = p.next;
			n++;
		}

		if (n == i) return p;

		return null;
	}


	public SinglyLinkedList get_previous(SinglyLinkedList begin, SinglyLinkedList node) {

		if ((begin == null) || (node == null)) return null;

		SinglyLinkedList p = begin;

		while(p != null) {

			if (p.next == node) return p;

			p = p.next;
		}

		return null;
	}


	public boolean is_empty(SinglyLinkedList begin) {

		return begin == null;
	}


	public void print_list(SinglyLinkedList begin) {

		if (begin == null) {
			System.out.println("Empty list.");
			return;
		}

		System.out.println();

		System.out.print("List: ");

		SinglyLinkedList p = begin;

		while(p != null) {

			System.out.print(p.key + ", ");

			p = p.next;
		}

		System.out.println();
	}
}