Leetcode- 283 . Move Zeros

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Question:

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.

Topics: Array , Two Pointers

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

Solution:

1. Pointer i: Keeps track of the position where the next non-zero element should go.

2. Pointer j: Iterates over the entire array.

Plan:

• Start with i = 0 and j = 0.

• Traverse through the array:

  • Whenever nums[j] is non-zero, move it to position i, and then increment i.

  • Continue until you've gone through the entire array.

• After this loop, all non-zero elements will be in their correct positions, and i will indicate where the 0s should start.

Solution Code:

class Solution:

    def moveZeroes(self, nums: List[int]) -> None:

        """

        Do not return anything, modify nums in-place instead.

        """

        i = 0

        for j in range(len(nums)):

            if nums[j] != 0:

                nums[i], nums[j]= nums[j] ,nums[i]

                i = i  + 1

        return nums