leetcode--Remove Element

Given an array and a value, remove all instances of that value in place and return the new length.

Do not allocate extra space for another array, you must do this in place with constant memory.

The order of elements can be changed. It doesn’t matter what you leave beyond the new length.

Example:
Given input array nums = [3,2,2,3], val = 3

Your function should return length = 2, with the first two elements of nums being 2.

解题思路：使用双指针；思路有2两个，一个是移位+存储；另一个是移位+删除；

java版本1：

public class Solution {    public int removeElement(int[] nums, int val) {        if(nums.length==0) return 0;        int j=0;        for(int i=0;i<nums.length;i++){           if(nums[i]!=val){               nums[j++]=nums[i];           }       }       return j;    }}

java版本2：

public class Solution {    public int removeElement(int[] nums, int val) {        if(nums.length==0) return 0;        int i=0,j=nums.length-1;        while(i<=j){            if(nums[i]==val){                nums[i]=nums[j--];                continue;            }            i++;        }        return i;    }}