4.rs

struct Solution {}

impl Solution {
    pub fn move_zeroes(nums: &mut Vec<i32>) {
        let mut next_zero_opt: Option<usize> = None;

        for i in 0..nums.len() {
            let num = nums[i];
            if num != 0 && next_zero_opt.is_some() {
                let next_zero = next_zero_opt.unwrap();
                nums[next_zero] = num;
                nums[i] = 0;
                let new_zero_opt = nums[next_zero + 1 .. nums.len()]
                                    .iter()
                                    .enumerate()
                                    .find(|(_i, num)| **num == 0)
                                    .map(|(i, _num)| i + next_zero + 1);
                next_zero_opt = new_zero_opt;
            } else if num == 0 && next_zero_opt.is_none() {
                next_zero_opt = Some(i);
            }
    }
}

fn main() {
    let mut ints = vec![0,1,0,3,12];
    Solution::move_zeroes(&mut ints);
    print!("{:?}", ints);
}