Question

How to find the first repeated character in a string with Java

Answer 1

import java.util.HashSet; 
 
public class Main {
    static int get_first_repeated_character(String s) { 
        HashSet<Character> hs = new HashSet<>(); 
        int len = s.length();
   
        for (int i = 0; i < len; i++) { 
            if (hs.contains(s.charAt(i))) 
                return i;
            else
                hs.add(s.charAt(i)); 
        }
        return -1;
    }   
    public static void main(String args[]) {
        String s = "abcdxypcbop"; 
         
        int i = get_first_repeated_character(s); 
        
        if (i == -1) 
            System.out.println("Not found"); 
        else
            System.out.println(s.charAt(i)); 
    }
}
 
 
 
 
/*
run:
 
c
 
*/

 

70+ SQL courses for beginners and professionals