题目

image.png

思路

  • 使用虚拟节点和尾插法

    代码

    1.   public ListNode partition(ListNode head, int x) {
    2.       ListNode p1 = new ListNode(0);
    3.       ListNode p2 = new ListNode(0);
    4.       ListNode p3 = p1, p4 = p2;
    5.       while (head != null) {
    6.           if (head.val < x) {
    7.               p3.next = head;
    8.               p3 = p3.next;
    9.           } else {
    10.               p4.next = head;
    11.               p4 = p4.next;
    12.           }
    13.           head = head.next;
    14.       }
    15.       p3.next = p2.next;
    16.       p4.next = null;
    17.       return p1.next;
    18.   }
    分割链表