[283 - Move Zero]

🔗 LeetCode Link

Problem Description

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.

Idea

use two pointer so we only need to iterate once

Logic

1. set slow pointer to mark current index
2. set fast pointer and use it for iterating
3. use fast pointer to find non-zero element
4. swap the value between slow

Code (Java - Closed Interval)

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

        // set slow pointer
        int slow = 0;
        
        // use fast pointer in the loop
        for(int fast = 0; fast <= nums.length - 1; fast++){

            // exchange value when fast pointer point to non-zero element
            if(nums[fast] != 0){
                int tmp = nums[slow];

                // move slow pointer
                nums[slow++] = nums[fast];
                nums[fast] = tmp;
            }
        }
    }
}