arrays - 将零移动到数组编程练习末尾的性能

Question

我想知道为什么我对这个 LeetCode“移动零点”问题的解决方案比大多数其他提交都慢。有没有更好的方法来解决这个问题以使其更快？

题目如下:

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. You must do this in-place without making a copy of the array.

Example:

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

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

这是我的解决方案:

 func moveZeroes(_ nums: inout [Int]) {
    var index = 0
    for (i,n) in nums.enumerated()
    {
        if n != 0
        {
            nums[index] = n
            index += 1
        }
        
    }
    
    while index < nums.count
    {
        nums[index] = 0
        index += 1
    }
}

LeetCode 给了我这些统计数据:

Runtime: 52 ms, faster than 40.50% of Swift online submissions for Move Zeroes.
Memory Usage: 19.4 MB, less than 13.33% of Swift online submissions for Move Zeroes.

编辑 1:

如果我按如下方式解决问题，它不会移动末尾的零，

编辑 2:

Answer 1

这是适合您的 36 毫秒就地解决方案:

class Solution {
    func moveZeroes(_ nums: inout [Int]) {

        if nums.count < 2 {
            return
        }

        var j = 0

        while j < nums.count, nums[j] != 0 {
            j += 1
        }

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