Swift solution for LeetCode #283. Move Zeroes

• Ref: LeetCode
• My GitHub Repo: LeetCode_Swift
• Difficulty: Easy
• Topics: Array

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.

배열 ‘nums’가 주어지면 0이 아닌 원소의 순서를 유지하면서 모든 0을 끝으로 이동시키는 함수를 작성하세요.

Example

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.

Solution

• 배열을 순회하며 0이 아닌원소를 만날때마다 left 인덱스의 원소와 스왑한다.
• 0일때는 left 인덱스를 유지한다.

Submissions

• Runtime: 40 ms, faster than 89.99% of Swift online submissions for Move Zeroes.
• Memory Usage: 21.2 MB, less than 90.98% of Swift online submissions for Move Zeroes.

Code

func moveZeroes(_ nums: inout [Int]) {
    var left = 0

    for i in 0..<nums.count {
        if nums[i] != 0 {
            nums.swapAt(i, left)
            left += 1
        }
    }
}