Remove Element 

The order of elements can be changed. It doesn‘t matter what you leave beyond the new length.

思路：此题和26题一脉相承，算法上不难，详细如代码所看到的：

public class Solution {
    public int removeElement(int[] nums, int val) {
        int len = nums.length;
        int tempLen = len;
        int step = 0;//每个元素须要向前转移的距离
        for(int i = 0; i < len; i++){
            if(nums[i] == val){
                step++;//若相等步长+1
                tempLen--;//每个相等的元素长度降低1
            }else{
                nums[i-step] = nums[i];//元素前移n个步长
            }
        }
        return tempLen;
    }
}