26. Remove Duplicates from Sorted Array

题目：

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.

思路：

同样也是一道双指针的问题，一个指针遍历数组，另一个指针指向新数组的下一个位置，和27题的相邻指针思路很相似。

代码：

public class Solution {    public int removeDuplicates(int[] nums) {        int length = nums.length;        //处理特殊情况        if(nums == null || length == 0){return 0;}        if(length == 1){return 1;}        //用两个指针，一个用于遍历数组，另一个用于新数组的下一个位置        int val = nums[0], next = 1;        for(int i = 1; i < length; i++){            if(nums[i] != val){                nums[next] = nums[i];                val = nums[i];                next++;            }        }        return next;    }}