Move Zeroes 去除0且按照原来顺序返回

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:

1. You must do this in-place without making a copy of the array.
2. Minimize the total number of operations.

public class Solution {
    public void moveZeroes(int[] nums) {
        int temp;
        int ahead=nums.length;
        if(nums.length==0)
            return;
        for(int i=0;i<nums.length;i++){
            if(nums[i]==0){
               ahead=i;
               break;
            }
        }
        if (ahead==nums.length)
            return;
        for(int i=ahead+1;i<nums.length;i++){
            if(nums[i]!=0){
                temp=nums[i];
                nums[i]=nums[ahead];
                nums[ahead]=temp;
                ahead++;
            }
        }
    }
}
//保持相对顺序不变的去除0元素，如0, 1, 0, 3, 12变成1, 3, 12, 0, 0
public class Solution {
    public void moveZeroes(int[] nums) {
        for (int i = 0, j = 0; i < nums.length; ++i) {
            if (nums[i]!=0) {//java的if语句的表达式值必须是boolean类型
                int temp=nums[j];
                nums[j]=nums[i];
                nums[i]=temp;
                j++;
            }
        }
    }
};//人家的程序vs我的程序。对比啊，差别真是不要不要的