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.
此题可以使用insert index来做，具体是设置一个idx，然后遍历数组，遇到不等于0的数组元素，复制给idx，然后idx++，具体代码如下：
public class Solution {
public void moveZeroes(int[] nums) {
int idx = 0;
for(int i=0;i<nums.length;i++){
if(nums[i]!=0){
nums[idx++] = nums[i];
}
}
for(int i=idx;i<nums.length;i++){
nums[i] = 0;
}
}
}