Help me in solving SUMNEQ7 problem

help
,
1

My issue

this is failing on 2nd subtask need help

My code

/* package codechef; // don't place package name! */

import java.util.*;
import java.lang.*;
import java.io.*;

/* Name of the class has to be "Main" only if the class is public. */
class Codechef
{
	public static void main (String[] args) throws java.lang.Exception
	{
		Scanner sc = new Scanner(System.in);
		int t = sc.nextInt();
		while(t-->0)
		{
		    int n = sc.nextInt();
		    long a[] = new long[n];
		    boolean flag = false;
		    for(int i=0;i<n;i++)
		    {
		        a[i] = sc.nextLong();
		    }
		    for(int i=0 , j = n-1;i<n && j>0;i++ , j--)
		    {
		        int x = i+1;
		        int y = j-1;
		        while(x<y)
		        {
		            if((a[i]+a[x])==(a[j]+a[y]))
		            {
		               x++;
		               y--;
		            }
		            else
		            {
		                flag = true;
		                break;
		            }
		        }
		        if(flag)
		            break;
		    }
		    if(flag)
		        System.out.println("yes");
		    else
		        System.out.println("no");
		}
	}
}

Problem Link: Sum Neq Practice Coding Problem - CodeChef