Given a sorted array, remove the duplicates in place such that each element appear only once and return the new length.
Do not allocate extra space for another array, you must do this in place with constant memory.
For example,
Given input array nums = [1,1,2],
Your function should return length = 2, with the first two elements of nums being 1 and 2 respectively. It doesn't matter what you leave beyond the new length.
PS: 这里虽然返回int值，但实际上打印出来的是原来数组的前n个值。
所以修改需要在原来的数组中修改，后面的数字可以忽略不管。
Run Code Result:
Your input
[1,1,2,2,2,3,4,4,4,4,4,5,6,7,8,9,9,9]
Your answer
[1,2,3,4,5,6,7,8,9]
Expected answer
[1,2,3,4,5,6,7,8,9]
class Solution { public int removeDuplicates(int[] nums) { if(nums.length <= 1) return nums.length; int index = 0; nums[index++] = nums[0]; for(int i=1; i<nums.length; i++){ if(nums[index-1] != nums[i]){ nums[index++] = nums[i]; } } return index; }}