leetcode ListNode类--Java

 public class ListNode {
     public int val;
     public ListNode next;
     public ListNode() {}
     public ListNode(int val) { this.val = val; }
     public ListNode(int val, ListNode next) { this.val = val; this.next = next; }

     public static ListNode generator(int[] arr) {
         ListNode l1 = new ListNode();
         ListNode head = l1;
         for (int i = 0, len = arr.length; i < len; i++) {
             l1.val = arr[i];
             if (i == len - 1) break;
             l1.next = new ListNode();
             l1 = l1.next;
         }
         return head;
     }

     public static void print(ListNode node) {
         while (node != null) {
             System.out.print(node.val + " ");
             node = node.next;
         }
         System.out.println("");
     }
 }