Move Zeroes · Interview Problem

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Leetcode

Medium

Arrays

Two Pointers

Greedy

Move Zeroes

Move all zeroes to the end of the array while preserving the relative order of the non-zero elements.

Acceptance 0%

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Problem Statement

Problem

Given an integer array, reorder it in place so that all 0 values are moved to the end while the relative order of the non-zero values remains unchanged.

You must modify the array directly and avoid using extra space proportional to the input size.

Goal

After the transformation:

every non-zero element should appear before every zero
the non-zero elements should stay in their original order
the array length must remain the same

Input Format

A list of integers nums
The array may contain positive, negative, and zero values

Output Format

Modify nums in place
Return nothing, or return the modified array depending on the language convention

Constraints

$1 \le nums.length$
Elements may be any 32-bit signed integers
Aim for $O(n)$ time and $O(1)$ extra space

Examples

Sample cases returned by the problem API.

Example 1

Input

nums = [0,1,0,3,12]

Output

[1,3,12,0,0]

Explanation

The non-zero values 1, 3, and 12 keep their original order, and the zeroes are moved to the end.

Example 2

Input

nums = [0,0,1]

Output

[1,0,0]

Explanation

Only one non-zero value exists, so it is placed first and the zeroes follow.

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