283. Move Zeroes

EasyLeetCode

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

How to solve the problem

• Two pointers(slow and fast)

class Solution:
    def moveZeroes(self, nums: List[int]) -> None:
        slow = 0
        for fast in range(len(nums)):
            if nums[fast] != 0:
                nums[fast], nums[slow] = nums[slow], nums[fast]
                slow += 1

Complexity

• Two Pointers: Time complexity: O(n), Space complexity: O(1)
  • Each element is visited once, and we only use constant extra space