劍指 Offer 22. 鏈表中倒數(shù)第k個(gè)節(jié)點(diǎn)

class Solution {
    public ListNode getKthFromEnd(ListNode head, int k) {
        // 統(tǒng)計(jì)長(zhǎng)度
        ListNode nodeLen=head;
        int len=0;
         while(nodeLen!=null){
             len++;
             nodeLen=nodeLen.next;
         }
         len=len-k;
         ListNode node=head;
          while(len>0){
             len--;
           node=node.next;
         }
         return node;


    }
}

劍指 Offer 18. 刪除鏈表的節(jié)點(diǎn)

找個(gè)節(jié)點(diǎn)當(dāng)作找到的節(jié)點(diǎn)，然后

class Solution {
    public ListNode deleteNode(ListNode head, int val) {
       

        if(head.val==val){
           return head.next;

        }
         ListNode node=head;
        
        
        while(node!=null){
          
            if(node.val==val){
                break;
            }
            node=node.next;
        }
        ListNode root=head;
         while(root!=null){
             if(root.next.val==val){
                 root.next=node.next;
                 break;
             }
             root=root.next;

         }

        return head;

    }
}