Merge Two Sorted Lists @LeetCode

Merge two sorted linked lists and return it as a new list. The new list should be made by splicing together the nodes of the first two lists.

	package leetcode.linkedlist;
	/**
	* Solution: Better to create a dummy node as first node which makes works easier.
	* Just simple problem, no algorithm in it. Take care of some details and make codes clean.
	*
	* @author jeffwan
	* @date Feb 16, 2014
	*/
	public class MergeTwoLists {
	public ListNode mergeTwoLists(ListNode l1, ListNode l2) {
	ListNode dummy = new ListNode(0);
	ListNode head = dummy;
	while(l1 != null && l2 != null) {
	if (l1.val <= l2.val) {
	head.next = l1;
	l1 = l1.next;
	} else {
	head.next = l2;
	l2 = l2.next;
	}
	head = head.next;
	}
	if (l1 != null) {
	head.next = l1;
	}
	if (l2 != null) {
	head.next = l2;
	}
	return dummy.next;
	}
	class ListNode {
	int val;
	ListNode next;
	ListNode (int x) {
	this.val = x;
	}
	}
	}

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