https://leetcode.com/problems/remove-duplicates-from-sorted-array-ii/description/
Follow up for "Remove Duplicates":
What if duplicates are allowed at most twice?
For example,
Given sorted array nums = [1,1,1,2,2,3],
Your function should return length = 5, with the first five elements of nums being 1, 1, 2, 2 and 3.
It doesn't matter what you leave beyond the new length.
1 public int removeDuplicates(int[] nums) {
2 if (nums == null || nums.length <= 2){
3 return nums.length ;
4 }
5
6 //slow pointer: 启示的位置 从2开始
7 int slow = 2 ;
8 //fast pointer
9 /* s
10 2 2 3
11 1, 1, 1, 2, 2, 3
12 i
13 * */
14 for (int i = 2; i < nums.length; i++) {
15 if (nums[slow-2] != nums[i]){
16 nums[slow++] = nums[i];
17 }
18 }
19 return slow;
20 }
