/** * Source : https://oj.leetcode.com/problems/remove-duplicates-from-sorted-list-ii/ * * * Given a sorted linked list, delete all nodes that have duplicate numbers, * leaving only distinct numbers from the original list. * * For example, * Given 1->2->3->3->4->4->5, return 1->2->5. * Given 1->1->1->2->3, return 2->3. */public class RemoveDuplicates2 {    /**     * 移除链表中所有重复的元素     *     * @param head     * @return     */    public Node remove (Node head) {        Node dummy = new Node();        dummy.next = head;        Node cur = head;        Node pre = dummy;        boolean duplicated = false;        while (cur != null && cur.next != null) {            if (cur.value == cur.next.value) {                cur.next = cur.next.next;                duplicated = true;            } else if (duplicated) {                // 如果出现重复则移除重复的元素                pre.next = cur.next;                cur = pre.next;                duplicated = false;            } else {                pre = cur;                cur = cur.next;            }        }        if (duplicated) {            pre.next = cur.next;        }        head = dummy.next;        return head;    }    private static class Node  implements Comparable
    
     {        int value;        Node next;        @Override        public String toString() {            return "Node{" +                    "value=" + value +                    ", next=" + (next == null ? "" : next.value) +                    '}';        }        @Override        public int compareTo(Node o) {            return this.value - o.value;        }    }    private static void print (Node node) {        while (node != null) {            System.out.println(node);            node = node.next;        }        System.out.println();    }    public Node createList (int[] arr) {        if (arr.length == 0) {            return null;        }        Node head = new Node();        head.value = arr[0];        Node pointer = head;        for (int i = 1; i < arr.length; i++) {            Node node = new Node();            node.value = arr[i];            pointer.next = node;            pointer = pointer.next;        }        return head;    }    public static void main(String[] args) {        RemoveDuplicates2 removeDuplicates2 = new RemoveDuplicates2();        int[] arr = new int[]{1,1,2};        int[] arr1 = new int[]{1,1,2,3,3};        int[] arr2 = new int[]{1,1,2,3,3,3,4,4,5};        print(removeDuplicates2.remove(removeDuplicates2.createList(arr)));        print(removeDuplicates2.remove(removeDuplicates2.createList(arr1)));        print(removeDuplicates2.remove(removeDuplicates2.createList(arr2)));    }}