283. Move Zeroes
- Total Accepted: 127538
- Total Submissions: 272915
- Difficulty: Easy
- Contributors: Admin
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.
For example, given nums = [0, 1, 0, 3, 12]
, after calling your function, nums
should be [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.
Code
class Solution(object): def moveZeroes(self, nums): """ :type nums: List[int] :rtype: void Do not return anything, modify nums in-place instead. """ # maintain how many zeroes we have seen count0 = 0 for idx, v in enumerate(nums): if v != 0: if count0 > 0: nums[idx-count0] = v nums[idx] = 0 else: count0 += 1
Idea
An element should be moved count0
ahead, where count0
records how many zeroes we have seen.
If the order of non-zero elements is not required to maintain, we can have another algorithm:
class Solution(object): def moveZeroes(self, nums): """ :type nums: List[int] :rtype: void Do not return anything, modify nums in-place instead. """ start, end = 0, len(nums)-1 while start < end: if nums[start] == 0: nums[start], nums[end] = nums[end], nums[start] end -= 1 else: start += 1