283. 移动零

[0,1,0,3,12]

class Solution:
    def moveZeroes(self, nums: List[int]) -> None:
        """
        Do not return anything, modify nums in-place instead.
        """
        if not nums:
            return
        n = len(nums)
        zero_count = 0
        for i in range(n):
            if nums[i] == 0:
                zero_count += 1
            else:
                nums[i - zero_count] = nums[i]
        while zero_count > 0:
            nums[n - zero_count] = 0
            zero_count -= 1

class Solution {
    public void moveZeroes(int[] nums) {
        int n;
        if (nums == null || (n = nums.length) < 1) {
            return;
        }
        int zeroCount = 0;
        for (int i = 0; i < n; ++i) {
            if (nums[i] == 0) {
                ++zeroCount;
            } else {
                nums[i - zeroCount] = nums[i];
            }
        }
        while (zeroCount > 0) {
            nums[n - zeroCount--] = 0;
        }
    }
}

/**
 * @param {number[]} nums
 * @return {void} Do not return anything, modify nums in-place instead.
 */
var moveZeroes = function (nums) {
    if (!nums.length) return nums;
    let j = 0;
    for (i = 0; i < nums.length; i++) {
        if (nums[i]) {
            if (i > j) [nums[i], nums[j]] = [nums[j], nums[i]];
            j++;
        }
    }
    return nums;
};