Problem:
Score : 200 points

Problem Statement

Let S(n) denote the sum of the digits in the decimal notation of n.
For example, S(101) = 1 + 0 + 1 = 2.

Given an integer N, determine if S(N) divides N.

Constraints

1 \leq N \leq 10^9

Input

Input is given from Standard Input in the following format:

N

Output

If S(N) divides N, print Yes; if it does not, print No.

Sample Input 1

12

Sample Output 1

Yes

In this input, N=12.
As S(12) = 1 + 2 = 3, S(N) divides N.

Sample Input 2

101

Sample Output 2

No

As S(101) = 1 + 0 + 1 = 2, S(N) does not divide N.

Sample Input 3

999999999

Sample Output 3

Yes

Solution in Rust (1.15.1) (judge verdict: Accepted)

#[allow(unused_imports)]
use std::cmp::{max, min};

struct Scanner {
    ptr: usize,
    length: usize,
    buf: Vec<u8>,
    small_cache: Vec<u8>,
}

#[allow(dead_code)]
impl Scanner {
    // from kenkoooooo
    fn new() -> Scanner {
        Scanner {
            ptr: 0,
            length: 0,
            buf: vec![0; 1024],
            small_cache: vec![0; 1024],
        }
    }

    fn load(&mut self) {
        use std::io::Read;
        let mut s = std::io::stdin();
        self.length = s.read(&mut self.buf).unwrap();
    }

    fn byte(&mut self) -> u8 {
        if self.ptr >= self.length {
            self.ptr = 0;
            self.load();
            if self.length == 0 {
                self.buf[0] = b'\n';
                self.length = 1;
            }
        }

        self.ptr += 1;
        return self.buf[self.ptr - 1];
    }

    fn is_space(b: u8) -> bool {
        b == b'\n' || b == b'\r' || b == b'\t' || b == b' '
    }

    fn read_vec<T>(&mut self, n: usize) -> Vec<T>
    where
        T: std::str::FromStr,
        T::Err: std::fmt::Debug,
    {
        (0..n).map(|_| self.read()).collect()
    }

    fn usize_read(&mut self) -> usize {
        self.read()
    }

    fn read<T>(&mut self) -> T
    where
        T: std::str::FromStr,
        T::Err: std::fmt::Debug,
    {
        let mut b = self.byte();
        while Scanner::is_space(b) {
            b = self.byte();
        }

        for pos in 0..self.small_cache.len() {
            self.small_cache[pos] = b;
            b = self.byte();
            if Scanner::is_space(b) {
                return String::from_utf8_lossy(&self.small_cache[0..(pos + 1)])
                    .parse()
                    .unwrap();
            }
        }

        let mut v = self.small_cache.clone();
        while !Scanner::is_space(b) {
            v.push(b);
            b = self.byte();
        }
        return String::from_utf8_lossy(&v).parse().unwrap();
    }
}

fn main() {
    let mut sc = Scanner::new();
    let n: i64 = sc.read();
    let mut m = n;
    let mut s = 0;
    while m != 0 {
        s += m % 10;
        m /= 10;
    }
    if n % s == 0 {
        println!("Yes");
    } else {
        println!("No");
    }
}