問題描述

給定一個排序連結串列，刪除所有重複的元素，使得每個元素只出現一次。

示例 1:

輸入: 1->1->2
輸出: 1->2

示例 2:

輸入: 1->1->2->3->3
輸出: 1->2->3

簡單的一批，直接程式碼

預設節點類

/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode(int x) { val = x; }
 * }
 */
 

 public ListNode deleteDuplicates(ListNode head) {
        if (head == null || head.next == null) {
            return head;
        }
        ListNode pre = head;
        ListNode next = head.next;

        while (next.next != null) {
            if (next.val == pre.val) {
                next = next.next;
                pre.next = next;
            }else {
                pre = next;
                next = next.next;
            }
        }
        if (next.val == pre.val){
            pre.next = null;
        }
        return  head;
    }
 

下邊是大神寫的

public ListNode deleteDuplicates(ListNode head) {
    ListNode current = head;
    while (current != null && current.next != null) {
        if (current.next.val == current.val) {
            current.next = current.next.next;
        } else {
            current = current.next;
        }
    }
    return head;
}