kSorted.java

public class kSorted {
    
}
/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode() {}
 *     ListNode(int val) { this.val = val; }
 *     ListNode(int val, ListNode next) { this.val = val; this.next = next; }
 * }
 */
class Solution {
    public ListNode mergeKLists(ListNode[] lists) {

        if(lists == null){
            return lists;
        }
        ListNode list = new ListNode();
        int i = 0;
        while(i < lists.length){
            list = mergeKLists(lists[i], list);

        }
        return list;

    }
    public ListNode mergeTwoLists(ListNode l1, ListNode l2) {
        if(l1 == null){ return l2; }
        else if(l2==null){ return l1; }
        ListNode head ;
        if(l1.val < l2.val ){ 
            head = l1;
            l1=l1.next;
        }
        else{
            head = l2;
            l2=l2.next;
        }
        ListNode ansH = head;
        ListNode temp = head;
        
        while(l1 != null || l2 != null){
            if(l1 == null){ head.next = l2; break;}
            else if(l2 == null){head.next = l1; break;}
            if(l1.val < l2.val){ 
                head.next = l1;
                l1=l1.next;
            }
            else {
               
                head.next = l2;
                l2=l2.next;
            }
            head= head.next;
            

        }
        return ansH;
    }
}