merge-two-sorted-lists

/**
*
* @author gentleKay
* 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.
*
* 合并两个已排序的链接列表并将其作为新列表返回。
* 新列表应该通过拼接前两个列表的节点来创建。
*/

/**
 * 
 * @author gentleKay
 * 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.
 * 
 * 合并两个已排序的链接列表并将其作为新列表返回。
 * 新列表应该通过拼接前两个列表的节点来创建。
 */

public class Main26 {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		ListNode l1 = new ListNode(1);
		l1.next = new ListNode(3);
		l1.next.next = new ListNode(5);
		
		ListNode l2 = new ListNode(2);
		l2.next = new ListNode(4);
		l2.next.next = new ListNode(6);
		l2.next.next.next = new ListNode(8);
		System.out.println(Main26.mergeTwoLists(l1, l2).val);
	}
	
	public static class ListNode {
		int val;
		ListNode next;
		ListNode(int x) {
			val = x;
			next = null;
		}
	}
	
	public static ListNode mergeTwoLists(ListNode l1, ListNode l2) {

        ListNode head = new ListNode(0);
        ListNode p = head;
        while (l1 != null && l2 != null) {
        	if (l1.val < l2.val) {
        		p.next = l1;
        		l1 = l1.next;
        	}else {
        		p.next = l2;
        		l2 = l2.next;
        	}
        	p = p.next;
        }
        
        if (l1 != null) {
        	p.next = l1;
        }
        if (l2 != null) {
        	p.next = l2;
        }
        return head.next;
    }
}