题解 | #提取不重复的整数#

use std::io::{self, *};
use std::collections::HashSet;


fn main() {
    let stdin = io::stdin();
    unsafe {
        for line in stdin.lock().lines() {
            let ll = line.unwrap();
            let mut numbers: Vec<&str> = ll.split("").filter(|&x| !x.is_empty()).collect();
            numbers.reverse();
            let mut uniques = HashSet::new();
            numbers.retain(|e| uniques.insert(*e));
            let res = numbers.into_iter().collect::<String>();
            println!("{:}", res);
        }
    }
}