283 Move Zeroes from Leetcode

Move Zeroes from Leetcode (Easy)

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.

Example:

Input: [0,1,0,3,12]
Output: [1,3,12,0,0]

Note:

1. You must do this in-place without making a copy of the array.
2. Minimize the total number of operations.

I'll share the javascript solution for the Move Zeroes problem from leetcode. It has O(n) time complexity.

Optimized for many zeroes

const snowball1 = nums => {
  let i = 0;
  let j = 0;
  while (i<nums.length) {
    if(nums[i] != 0) {
      nums[j] = nums[i];
      j++;
    }
    i++;
  }
  console.log(j);
  nums.fill(0, j);
  return nums;
}

Optimized for fewer zeroes

const snowball2 = nums => {
  for(let i = nums.length; i--;){
    if(nums[i]===0){
      nums.splice(i,1)
      nums.push(0);
    }
  }
  return nums
}

Example

console.log(snowball1([0,0,1,0,0,3,0,12,0]));
console.log(snowball2([0,1,0,3,12]));

Result

[ 1, 3, 12, 0, 0, 0, 0, 0, 0 ]
[ 1, 3, 12, 0, 0 ]