Review: ArrayList Operations --

Hey… I’ve been stuck at this question for quite some time now… Review: ArrayList Operations – CodeChef | Competitive Programming | Participate & Learn
All sample test cases are passing but still getting wrong answer while submitting… not able to figure out which test case it is failing for

Here’s my code :

import java.util.*;

class Codechef
public static void main (String[] args)
Scanner read = new Scanner(;
int t = read.nextInt();
for(int i=0; i<t; i++)
ArrayList a = new ArrayList();
int n = read.nextInt();
for(int j=1; j<=n; j++){
int ele = read.nextInt();
// Update the code below to solve this problem
for(int j=0; j<a.size()-1;){
if(j<a.size()-1 && a.get(j)==a.get(j+1) || j>0 && a.get(j)==a.get(j-1)){
else j++;