golang中怎么合并K个排序链表

/** * Definition for singly-linked list. * type ListNode struct { *     Val int *     Next *ListNode * } */func mergeKLists(lists []*ListNode) *ListNode {    k:=len(lists)    if k==0{        return nil    }    for k>1{        if k%2==1{                lists[0]=merge(lists[0],lists[k-1])        }        k/=2        for i:=0;i            lists[i]=merge(lists[k+i],lists[i])        }
    }    return lists[0]}
func merge(l1,l2 *ListNode)*ListNode{    h:=&ListNode{}    tmp:=h    for l1!=nil && l2!=nil{        if l1.Val            tmp.Next=l1            l1=l1.Next        }else{            tmp.Next=l2            l2=l2.Next        }        tmp=tmp.Next    }    if l1!=nil{        tmp.Next=l1    }        if l2!=nil{        tmp.Next=l2    }    return h.Next}