What is the main pattern used in Move Zeroes?

The primary pattern is two-pointer scanning with invariant tracking, where one pointer scans and the other tracks the next position for non-zero elements.

Do I need extra space to solve Move Zeroes?

No, the problem must be solved in-place, modifying the input array without allocating additional arrays.

Can I swap zeros with non-zeros multiple times?

Minimize swaps by only moving non-zero elements when they are not already in the correct position, ensuring efficiency.

How does GhostInterview verify Move Zeroes solutions?

It simulates each step of your two-pointer approach, showing the state of the array after every move to catch ordering mistakes.

What are common mistakes when solving Move Zeroes?

Creating extra arrays, ignoring relative order of non-zero elements, or performing unnecessary swaps with zeros are frequent errors.

#283

Easy

auto_awesome双·指针·invariant

LeetCode 题解工作台

移动零

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。请注意，必须在不复制数组的情况下原地对数组进行操作。示例 1: 输入: nums = [0,1,0,3,12] 输出: [1,3,12,0,0] 示例 2: 输入: nums = [0] 输出: […

数组双指针

题目描述

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。

请注意 ，必须在不复制数组的情况下原地对数组进行操作。

示例 1:

输入: nums = [0,1,0,3,12]
输出: [1,3,12,0,0]

示例 2:

输入: nums = [0]
输出: [0]

提示:

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

进阶：你能尽量减少完成的操作次数吗？

lightbulb

解题思路

方法一：双指针

我们用一个指针 $k$ 记录当前待插入的位置，初始时 $k = 0$ 。

然后我们遍历数组 $\textit{nums}$ ，每次遇到一个非零数，就将其与 $\textit{nums}[k]$ 交换，同时将 $k$ 的值加 $1$ 。

这样我们就可以保证 $\textit{nums}$ 的前 $k$ 个元素都是非零的，且它们的相对顺序与原数组一致。

时间复杂度 $O(n)$ ，其中 $n$ 是数组 $\textit{nums}$ 的长度。空间复杂度 $O(1)$ 。

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class Solution:
    def moveZeroes(self, nums: List[int]) -> None:
        k = 0
        for i, x in enumerate(nums):
            if x:
                nums[k], nums[i] = nums[i], nums[k]
                k += 1

speed

复杂度分析

指标	值
时间	complexity is O(n) since each element is visited at most once. Space complexity is O(1) because the rearrangement occurs in-place without additional arrays.
空间	Depends on the final approach

psychology

面试官常问的追问

外企场景

question_mark
Watch for attempts to create a copy of the array instead of in-place rearrangement.
question_mark
Check if candidates maintain the relative order of non-zero elements while moving zeros.
question_mark
Look for correct use of a two-pointer invariant to minimize unnecessary swaps.

warning

常见陷阱

外企场景

error
Swapping elements unnecessarily even when non-zero is already in place.
error
Failing to handle arrays where all elements are zeros or all non-zeros.
error
Using extra memory instead of modifying the input array directly.

swap_horiz

进阶变体

外企场景

arrow_right_alt
Move all occurrences of a specific number to the end while preserving order.
arrow_right_alt
Partition an array into even and odd numbers using a similar two-pointer approach.
arrow_right_alt
Move zeros to the beginning instead of the end while keeping non-zero order.

help

常见问题

外企场景

继续练习

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