i can't get it to work this code for Deja Vu why?

Question

import java.util.Scanner;
public class Program
{
public static void main(String[] args) {
Scanner sc=new Scanner(System.in);
String word=sc.nextLine();
char[]arr=word.toCharArray();
int i=0;
while(i<arr.length-1){
i++;
}
if(arr[i]==arr[i+1]){
System.out.println("Deja Vu");
}else{
System.out.println("Unique");
}

}
}

Answer 1

Your conditions are not inside the while loop. there are lots of bugs, and logic error.

https://code.sololearn.com/cRyrscxrobCp/?ref=app

Answer 2

while(i<arr.length-1) {
i++;
}
this loop do nothing but increases i

then one time you compare two characters in close positions together, like "aabbcc"
but there can be "abcd abcd" which are also repeating