Rust Sort 0's to back

sort-back.rs

// Your last Rust code is saved below:
fn move_to_back(v: &Vec<u32>) -> Vec<u32> {
  // extra memory
  let mut res = vec![];
  let mut num_of_zeros = 0;
  for i in v.iter() {
    if *i != 0 as u32 {
      res.push(*i); 
    } else {
      num_of_zeros += 1;
    }
  }
  
  res.sort(); 
  
  while num_of_zeros != 0 {
    res.push(0 as u32);
    num_of_zeros -= 1;
  }
  
  res
}

fn move_to_back_in_place(v: &mut Vec<u32>) -> Vec<u32> {
  v.sort();
  // if value in vector is 0, we will mark this as sorted last (ascending)
  v.sort_by_key(|a| *a == 0);
  v.to_vec()
}

fn main() {
  let input = vec![1, 0, 0, 2, 3, 4, 0, 6];
  let res = move_to_back(&input);
  dbg!(res);
  
  let input = vec![1, 2, 3, 4, 8, 6];
  let res = move_to_back(&input);
  dbg!(res);
  
  let mut input = vec![1, 0, 0, 2, 3, 4, 8, 6, 0];
  let res = move_to_back_in_place(&mut input);
  dbg!(res);
}