Delete N Nodes After M Nodes of a Linked List

给一个链表, 删除m个node后边的n个node.

这个题就是corner cases多…

/**
 * 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 deleteNodes(ListNode head, int m, int n) {
        ListNode dummy = new ListNode(-1);
        dummy.next = head;
        ListNode cur = dummy;
        while(cur != null){
            int t = m;
            int tt = n;
            while(t-- > 0){
                if(cur == null)
                    return head;
                 cur = cur.next;
            }
            while(tt -- >0){
                if(cur == null || cur.next == null)
                    return head;
                cur.next = cur.next.next;
           }
        }
        return head;
    }
}