Problem:
Score : 200 points

Problem Statement

You are given a string S consisting of lowercase English letters. Determine whether all the characters in S are different.

Constraints

2 ≤ |S| ≤ 26, where |S| denotes the length of S.

S consists of lowercase English letters.

Input

Input is given from Standard Input in the following format:

S

Output

If all the characters in S are different, print yes (case-sensitive); otherwise, print no.

Sample Input 1

uncopyrightable

Sample Output 1

yes

Sample Input 2

different

Sample Output 2

no

Sample Input 3

no

Sample Output 3

yes

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


#![allow(unused)]

use std::cmp;
use std::io::{self, BufRead};
use std::iter;

macro_rules! destruct_ {
  ($e: expr, ()) => (
    assert!($e.next().is_none())
  );
  ($e: expr, ($arg: ident, $( $args: ident, )*)) => (
    $arg = $e.next().unwrap();
    destruct_!($e, ($($args,)*))
  );
  ($e: expr, ($arg: ident $(, $args: ident )*)) => (
    $arg = $e.next().unwrap();
    destruct_!($e, ($($args,)*))
  );
}

macro_rules! into {
  ($e: expr, $($name: ident)*) => {
    let mut iter = $e.into_iter();
    destruct_!(iter, ($($name)*));
  }
}

macro_rules! get {
  ($i: ident) => (
    let stdin = io::stdin();
    let mut $i = Vec::new();
    for line in stdin.lock().lines() {
      $i.push(
        line
          .unwrap()
          .split_whitespace()
          .map(|a| a.parse().unwrap())
          .collect()
      );
    }
  )
}

macro_rules! p {
  ($a: expr) => (
    println!("{}", $a);
  )
}

macro_rules! pp {
  ($a: expr) => (
    println!("{:?}", $a);
  )
}

fn main() {
  let mut args: Vec<Vec<String>>;
  let mut ss: Vec<String>;
  let mut s: String;
  get!(args);
  into!(args, ss);
  into!(ss, s);

  let bs = s.as_bytes();
  for a in 0 .. bs.len() {
    for b in 0 .. bs.len() {
      if a != b && bs[a] == bs[b] {
        p!("no");
        return;
      }
    }
  }
  p!("yes");
}