移动零

题目

给定一个数组 nums, 编写一个函数将所有 0 移动到数组的末尾, 同时保持非零元素的相对顺序, 必须在原数组上操作, 不能拷贝额外的数组.

提示:

• 1 <= nums.length <= 10⁴
• -2³¹ <= nums[i] <= 2³¹ - 1

示例

输入: [0, 1, 0, 3, 6]

输出: [1, 3, 6, 0, 0]

题解

fast            fast            fast            fast            fast            fast
 ↓               ↓               ↓               ↓               ↓               ↓
[0 1 0 3 6]   [0 1 0 3 6]   [1 0 0 3 6]   [1 0 0 3 6]   [1 3 0 0 6]   [1 3 6 0 0]
 ↑             ↑               ↑             ↑               ↑               ↑
slow          slow            slow          slow             slow           slow

/**
 * @param {number[]} nums
 * @return {void} Do not return anything, modify nums in-place instead.
 */
var moveZeroes = function (nums) {
  const n = nums.length
  let slow = 0,
    fast = 0

  while (fast < n) {
    if (nums[fast] !== 0) {
      ;[nums[slow], nums[fast]] = [nums[fast], nums[slow]]
      slow++
    }
    fast++
  }
}