MoveZeroes.java

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// 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:

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


class Solution {
  public void moveZeroes(int[] nums) {
    if (nums.length == 0 || nums == null) { return; }

    for (int counter = 0, insertPosition = 0; counter < nums.length; counter++) {
      if (nums[counter] != 0 ) {
        swap(nums, counter, insertPosition++);
      }
    }
  }

  // https://betterexplained.com/articles/swap-two-variables-using-xor/
  private void swap(int[] nums, int i, int j) {
    if (nums[i] == nums[j]) { return; }
    nums[i] ^= nums[j];
    nums[j] ^= nums[i];
    nums[i] ^= nums[j];
  }
}