283. Move Zeroes

Problem

Given an array nums, write a function to move all 0's to the end of it while maintaining the relative order of the non-zero elements.

Example 1:

Input: [0,1,0,3,12]
Output: [1,3,12,0,0]

Note:

• You must do this in-place without making a copy of the array.
• Minimize the total number of operations.

Problem Summary

The problem requires not using any extra auxiliary space, moving all 0 elements in the array to the end of the array, while maintaining the relative positions of all non-zero elements.

Solution Approach

This problem can be solved by scanning the array only once, continuously using i and j to mark 0 and non-zero elements, then swapping them with each other, ultimately achieving the goal of the problem. Similar problems include Problem 26, Problem 27, and Problem 80.

Code

package leetcode

func moveZeroes(nums []int) {
	if len(nums) == 0 {
		return
	}
	j := 0
	for i := 0; i < len(nums); i++ {
		if nums[i] != 0 {
			if i != j {
				nums[i], nums[j] = nums[j], nums[i]
			} 
			j++
		}
	}
}