26. Remove Duplicates from Sorted Array

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.

问题描述：给定一个有序数组，去掉数组中重复的以保证每个元素只在数组中出现一次，返回去重后得到的新数组的长度。注：不要为另一个数组分配额外的空间，必须使用常量内存。

分析：循环遍历数组，定义变量i,j，首先i,j的值都为0，然后比较nums[i],nums[j]的值，若相等则i++，j不变；不相等时则j++，且nums[j]=nums[i]。j记录去重后的数组索引值，最后j++才是数组的长度。

public class Solution {    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]){        j++;        nums[j]=nums[i];        }        }        return ++j;     }}