How hard is LeetCode 2459. Sort Array by Moving Items to Empty Space?

LeetCode 2459. Sort Array by Moving Items to Empty Space is rated Hard on LeetCode.

What is the time complexity of LeetCode 2459. Sort Array by Moving Items to Empty Space?

The Python solution on this page runs in O(n).

What is the space complexity of LeetCode 2459. Sort Array by Moving Items to Empty Space?

The Python solution on this page uses O(n) auxiliary space.

What topics does LeetCode 2459. Sort Array by Moving Items to Empty Space cover?

LeetCode 2459. Sort Array by Moving Items to Empty Space is tagged Greedy, Array and Sorting on LeetCode.

Is LeetCode 2459. Sort Array by Moving Items to Empty Space a premium problem?

Yes. LeetCode 2459. Sort Array by Moving Items to Empty Space is a LeetCode Premium problem, so the full statement and test cases require a paid LeetCode subscription.

Sort Array by Moving Items to Empty Space — LeetCode 2459 Python Solution

HardLeetCode PremiumGreedyArraySorting

Problem: #2459
Pattern: Greedy
Reading time: 4 min
Source: leetcode.com

The problem

You are given an integer array nums of size n containing each element from 0 to n - 1 (inclusive). Each of the elements from 1 to n - 1 represents an item, and the element 0 represents an empty space.

Example

Input: nums = [4,2,0,3,1]
Output: 3
Explanation: - Move item 2 to the empty space. Now, nums = [4,0,2,3,1].

Python solution

Python

class Solution:
    def sortArray(self, nums: List[int]) -> int:
        def f(nums, k):
            vis = [False] * n
            cnt = 0
            for i, v in enumerate(nums):
                if i == v or vis[i]:
                    continue
                cnt += 1
                j = i
                while not vis[j]:
                    vis[j] = True
                    cnt += 1
                    j = nums[j]
            return cnt - 2 * (nums[k] != k)

        n = len(nums)
        a = f(nums, 0)
        b = f([(v - 1 + n) % n for v in nums], n - 1)
        return min(a, b)

Complexity

Measure	Complexity
Time	O(n)
Space	O(n) auxiliary

Pattern: Greedy

Take the locally best option every time — when you can prove that never costs you later. LeetCode 2459. Sort Array by Moving Items to Empty Space is filed here on both counts: the reference solution below belongs to the algorithm family this hub collects, and LeetCode tags it Greedy.

The greedy guide has the Python template for the pattern and the 346 LeetCode problems that use it.

Frequently asked questions

How hard is LeetCode 2459. Sort Array by Moving Items to Empty Space?: LeetCode 2459. Sort Array by Moving Items to Empty Space is rated Hard on LeetCode.
What is the time complexity of LeetCode 2459. Sort Array by Moving Items to Empty Space?: The Python solution on this page runs in O(n).
What is the space complexity of LeetCode 2459. Sort Array by Moving Items to Empty Space?: The Python solution on this page uses O(n) auxiliary space.
What topics does LeetCode 2459. Sort Array by Moving Items to Empty Space cover?: LeetCode 2459. Sort Array by Moving Items to Empty Space is tagged Greedy, Array and Sorting on LeetCode.
Is LeetCode 2459. Sort Array by Moving Items to Empty Space a premium problem?: Yes. LeetCode 2459. Sort Array by Moving Items to Empty Space is a LeetCode Premium problem, so the full statement and test cases require a paid LeetCode subscription.