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.

Solution

public class RemoveDuplicatesfromSortedArray {
public int removeDuplicates(int[] nums) {
if (nums.length == 0) return 0;

int j = 0;
for (int i = 0; i < nums.length; i++) {
if (nums[i] != nums[j])
nums[++j] = nums[i];
}
return ++j;
}
}

关键在于题目还要求对Nums进行去重复。所以不仅仅是统计不重复数的问题，还要把数据去重复。