移动零

public class Solution
{
    public void MoveZeroes(int[] nums)
    {
        int zeronum = 0;
        for (var i = 0; i < nums.Length; i++)
        {
            if (nums[i] == 0)
            {
                zeroNum++;
            }
            else
            {
                if (zeronum == 0)
                {

                }
                else
                {
                    //交换第一个0位置：i-zeronum
                    nums[i - zeroNum] = nums[i];
                    nums[i] = 0;
                }
            }
        }
    }
}

public class Solution
{
    public void MoveZeroes(int[] nums)
    {
        int arrLength = nums.Length;
        int left = 0;
        for (var right = 0; right < arrLength; right++)
        {
            if (nums[right] != 0)
            {
                nums[left] = nums[right];
                if (left != right) nums[right] = 0;
                left++;
            }
        }
    }
}

//双指针记录
public class Solution
{
    public void MoveZeroes(int[] nums)
    {
        int j = 1;
        for (var i = 0; i < nums.Length; i++)
        {
            if (nums[i] == 0)
            {
                while (j < nums.Length && nums[j] == 0)
                {
                    j++;
                }
                if (j >= nums.Length) return;
                nums[i] = nums[j];
                nums[j] = 0;
            }
            j++;
        }
    }
}