what's wrong in this code

Question

You aren't paying attention and you accidentally type a bunch of random letters on your keyboard. You want to know if you ever typed the same letter twice, or if they are all unique letters.
Task:
If you are given a string of random letters, your task is to evaluate whether any letter is repeated in the string or if you only hit unique keys while you typing.
Input Format:
A string of random letter characters (no numbers or other buttons were pressed).
Output Format:
A string that says 'Deja Vu' if any letter is repeated in the input string, or a string that says 'Unique' if there are no repeats.
Sample Input:
aaaaaaaghhhhjkll
Sample Output:
Deja Vu

Answer 1

Modify 2nd for loop to j<s.length()..
It's done!!

Answer 2

import java.util.Scanner;
class test {
int i, j;
boolean flag=true;
public void check(){
Scanner sc=new Scanner(System.in);
String s=sc.nextLine();
for(i=0;i<s.length()-1;i++)
{
for(j=i+1;j<s.length();j++)
{
if(s.charAt(i) ==s.charAt(j)) {
flag=false;
break;
}
}
}
if(flag==true)
System.out.println ("Unique") ;
else
System.out.println ("Deja Vu") ;
}
};
public class Program
{
public static void main(String[] args) {
test t=new test();
t. check();
}
}

Answer 3

This should be done

Answer 4

❤️💻Programmer💻❤️
As index start from 0 so if you do <= then it will go beyond the index and you get indexOutOfBound exception.
So either you do (j < s.length) or do ( j <= s.length - 1)
import java.util.Scanner;
class Test {
public boolean check(String s) {
int i, j;
boolean flag = true;
for (i = 0; i < s.length(); i++) {
for (j = i + 1; j < s.length(); j++) {
if (s.charAt(i) == s.charAt(j)) {
flag = false;
break;
}
}
}
return flag;
}
}
public class Program {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
String s = sc.nextLine();
Test t = new Test();
boolean flag = t.check(s);
System.out.print(flag ? "Unique" : "Deja Vu");
}
}