Envío 6977

Código

import java.util.HashMap;
import java.util.Scanner;

class Main {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);

        HashMap<Character, Integer> map = new HashMap<>();
        int index = 50;

        String text;
        text = scan.nextLine();

        scan.close();

        for (int i = 0; i < text.length(); i++) {
            char current = text.charAt(i);

            if (!map.containsKey(current)) {
                map.put(current, i);
            } else {
                if (map.get(current) < index) {
                    index = map.get(current);
                }
            }
        }

        if (index != 50) {
            System.out.println("yes");
        } else {
            System.out.println("no");
        }
    }
}