public class DuplicateCharacters {

public static void main(String[] args) {

String string1 = "Great responsibility";

int count;

//Converts given string into character array

char string[] = string1.toCharArray();

System.out.println("Duplicate characters in a given string: ");

//Counts each character present in the string

for(int i = 0; i <string.length; i++) {

count = 1;

for(int j = i+1; j <string.length; j++) {

if(string[i] == string[j] && string[i] != ' ') {

count++; //Set string[j] to 0 to avoid printing visited character

string[j] = '0';

}

}

//A character is considered as duplicate if count is greater than 1

if(count > 1 && string[i] != '0')

System.out.println(string[i]);

}

}

}