[Leedcode 23] Merge k Sorted Lists

/*** Definition for singly-linked list. * public class ListNode {* int val; * ListNode Next; * ListNode (int X) {val = x;}}*/ Public classSolution {//There are two kinds of solutions, one is to compare all the linked list, because each node needs to compare K times, total kn nodes so the time complexity is O (KNK)//the second one draws on the two-point sequencing method, T (k) =2t (K/2) +o (NK), and the time complexity is O (NKLOGK)     PublicListNode mergeklists (listnode[] lists) {if(lists.length<1)return NULL; if(lists.length==1)returnLists[0]; returnMerge1 (lists,0,lists.length-1); }     PublicListNode merge1 (listnode[] lists,intStartintend) {               if(start<end) {            intMid= (start+end)/2; ListNode L1=Merge1 (Lists,start,mid); ListNode L2=merge1 (lists,mid+1, end); returnMerge2 (L1,L2);//Two-point sorting}Else{            returnLists[start]; }    }         PublicListNode merge2 (listnode l1,listnode L2) {ListNode Newhead=NewListNode (-1); ListNode Temp=Newhead;  while(l1!=NULL&&l2!=NULL){            if(l1.val<l2.val) {Temp.next=L1; L1=L1.next; }Else{Temp.next=L2; L2=L2.next; } temp=Temp.next; }        if(l1!=NULL) {Temp.next=L1; }        if(l2!=NULL) {Temp.next=L2; }        returnNewhead.next; }}

[Leedcode 23] Merge k Sorted Lists