# Merge Two Sorted Lists

## Problem

Merge two sorted (ascending) linked lists and return it as a new sorted list. The new sorted list should be made by splicing together the nodes of the two lists and sorted in ascending order.

## Example

Given 1->3->8->11->15->null, 2->null , return 1->2->3->8->11->15->null.

## Code - Java

/**
* Definition for ListNode.
* public class ListNode {
*   int val;
*   ListNode next;
*   ListNode(int val) {
*     this.val = val;
*     this.next = null;
*   }
* }
*/
public class Solution {
/**
* @param ListNode l1 is the head of the linked list
* @param ListNode l2 is the head of the linked list
* @return: ListNode head of linked list
*/
public ListNode mergeTwoLists(ListNode l1, ListNode l2) {
ListNode head = new ListNode(0);
ListNode ptr = head;
while (l1 != null && l2 != null) {
if (l1.val < l2.val) {
ptr.next = l1;
l1 = l1.next;
} else {
ptr.next = l2;
l2 = l2.next;
}
ptr = ptr.next;
}

if (l1 != null) {
ptr.next = l1;
} else if (l2 != null) {
ptr.next = l2;
}

}