LeetCode 283. Move Zeroes

Description

https://leetcode.com/problems/move-zeroes/

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 <= 104
  • -231 <= nums[i] <= 231 - 1

Follow up: Could you minimize the total number of operations done?

Explanation

Two pointers. One faster, one slower. The slower pointer points to the first zero position. When the faster one finds a non-zero number, swap with the first zero.

Python Solution

class Solution:
    def moveZeroes(self, nums: List[int]) -> None:
        """
        Do not return anything, modify nums in-place instead.
        """
        
        i = 0
        j = 0
        
        while j < len(nums):
            if nums[j] != 0:
                temp = nums[i]
                nums[i] = nums[j]
                nums[j] = temp
                i += 1
            
            j += 1
  • Time complexity: O(N).
  • Space complexity: O(1).

2 Thoughts to “LeetCode 283. Move Zeroes”

  1. class Solution {
    public void moveZeroes(int[] nums) {

    if(nums.length == 0 || nums == null) return;

    int idx = 0;
    for(int i =0; i< nums.length;i++){
    if(nums[i] != 0){
    nums[idx++] = nums[i];
    }
    }

    while(idx < nums.length){
    nums[idx++] = 0;
    }

    return;

    }
    }

Leave a Reply

Your email address will not be published.