merge two sorted linked list with duplicates

Question:

Given two sorted linked list, and merge them without using extra space (using constant space is allowed). For example, if 1 -> 2 -> 5 merges with 2 -> 4 -> 5,  we have 1 ->  2 -> 4 -> 5

Analyze:

using four pointers: 

h1: point to the head of list 1

h2: point to the head of list 2;

small: the smaller head between h1 and h2;

prev: the last node in the "new" list;

public static Node mergeSortedListWithDuplicates(Node h1, Node h2) {//one or both of the list(s) is (are) nullif(h1 == null) return h2;if(h2 == null ) return h1;Node newHead = (h1.data <= h2.data) ? h1 : h2;Node small = null;Node prev = newHead;//proceed to compare two heads and until one of them is null while (h1 != null && h2 != null) {if (h1.data <= h2.data) {small = h1;h1 = h1.next;} else {small = h2;h2 = h2.next;}prev.next = small;prev = small;}//deal with the remaining part of h1 or h2if (h1 == null) prev.next = h2;if (h2 == null) prev.next = h1;return newHead;}

http:blog.csdn.net/beiyeqingteng