23.Merge k Sorted Lists --- leetcode

public static ListNode mergeKLists(ListNode[] lists){return partion(lists,0,lists.length-1);}public static ListNode partion(ListNode[] lists,int s,int e){if(s==e)  return lists[s];if(s<e){int q=(s+e)/2;ListNode l1=partion(lists,s,q);ListNode l2=partion(lists,q+1,e);return merge(l1,l2);}elsereturn null;}//This function is from Merge Two Sorted Lists.public static ListNode merge(ListNode l1,ListNode l2){if(l1==null) return l2;if(l2==null) return l1;if(l1.val<l2.val){l1.next=merge(l1.next,l2);return l1;}else{l2.next=merge(l1,l2.next);return l2;}}