Scala实现删除链表中倒数第n个元素（leetCode 19）

https://leetcode-cn.com/problems/remove-nth-node-from-end-of-list/
object Solution {
    def removeNthFromEnd(head: ListNode, n: Int): ListNode = {
        val len = getLength(head)
        if(len == 0){ //链表为空
            head
        }else{
            val preHead = new ListNode(-1,head)
            var cur = preHead
            //待删除节点的前驱节点
            val deleteNodeFormerLocation = len - n 
            for(i<-1 to deleteNodeFormerLocation){
                cur = cur.next
            }            
            cur.next = cur.next.next 
            preHead.next 
        }
    }

    //获取链表总长度
    def getLength(head:ListNode)={
        var cur = head
        var len = 0
        while(cur != null){
            len += 1
            cur = cur.next
        }
        len
    }      
}