Given an array nums, write a function to move all 0's to the end of it while maintaining the relative order of the non-zero elements.For example, given nums = [0, 1, 0, 3, 12], after calling your function, nums should be [1, 3, 12, 0, 0].Note:You must do this in-place without making a copy of the array.Minimize the total number of operations.

题目可以在O(n)时间复杂度内求解

算法步骤：

使用两个"指针"x和y，初始令y = 0

利用x遍历数组nums：

若nums[x]非0，则交换nums[x]与nums[y]，并令y+1

 

public class Solution {    public void moveZeroes(int[] nums) {        int fast=0;        int slow=0;        while(fast