283. Move Zeroes

🟩 Easy

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

Note that you must do this in-place without making a copy of the array.

Example 1

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

Example 2

Input: nums = [0] Output: [0]

Constraints

• 1 <= nums.length <= 10^4

• -2^31 <= nums[i] <= 2^31 - 1

Follow up: Could you minimize the total number of operations done?

Hint-1

In-place means we should not be allocating any space for extra array. But we are allowed to modify the existing array. However, as a first step, try coming up with a solution that makes use of additional space. For this problem as well, first apply the idea discussed using an additional array and the in-place solution will pop up eventually.

Hint-2

A two-pointer approach could be helpful here. The idea would be to have one pointer for iterating the array and another pointer that just works on the non-zero elements of the array.

Solution

My Solution

func moveZeroes(nums []int)  {
    idx := 0
    for _, num := range nums {
        if num != 0 {
            nums[idx] = num
            idx++
        }
    }

    for i:=idx; i<len(nums); i++ {
        nums[i]=0
    }
}

result

Leetcode: link