Easy 用时5分钟。
精简代码: version 1，未merge逻辑

public class Solution {
    public void moveZeroes(int[] nums) {
        int slow = 0;
        int length = nums.length;
        for (int i=0;i<length;i++){
            if(nums[i] != 0){
                if(nums[slow] != 0) slow ++;
                else{
                    swap(slow, i, nums);
                    slow ++;
                }
            }
        }
    }
    private void swap(int slow, int i, int[] nums){
        int temp = nums[i];
        nums[i] = nums[slow];
        nums[slow] = temp;
    }
}

Version2: merge if else

public class Solution {
    public void moveZeroes(int[] nums) {
        //8:38
        int slow = 0;
        int length = nums.length;
        for (int i=0;i<length;i++){
            if(nums[i] != 0){
                if(nums[slow] == 0) swap(slow, i, nums);
                slow ++;
            }
        }
    }
    private void swap(int slow, int i, int[] nums){
        int temp = nums[i];
        nums[i] = nums[slow];
        nums[slow] = temp;
    }
}