【Easy】112. Remove Duplicates from Sorted List

Given a sorted linked list, delete all duplicates such that each element appear only once.

Example:

Given 1->1->2, return 1->2. Given 1->1->2->3->3, return 1->2->3.

解题思路

维护两个指针，slow指向当前检测到的元素，fast指向slow之后第一个和slow不一样的元素。

核心代码

    while (slow != null){
        while (fast != null && slow.val == fast.val){
            if (fast.next != null) fast = fast.next;
            else fast = null;
        }
        slow.next = fast;
        slow = fast;
    }

时间空间复杂度

O(n) + S(1)