Agfdhyk

Input: First line of input contains a single integer T which denotes the number of test cases. T test cases follows, first line of each test case contains a integer n. Second line consists of n spaced integers.

Output: Print the elements of the stack after deleting the middle element in reverse order.

Input:1

7

1 2 3 4 5 6 7

output is:

7 6 5 3 2 1

actually i am able to do printing in reverse fashion but i don't know how to remove middle element from the stack.please help

import java.util.*;

import java.lang.*;

import java.io.*;

class GFG

{

public static void main (String args)

{

    Scanner s=new Scanner(System.in);

    int test=s.nextInt();

    for(int t=0;t<test;t++)

    {

        int n=s.nextInt();

        int a=new int[n];

        for(int i=0;i<n;i++)

            a[i]=s.nextInt();

        Stack<Integer> stack=new Stack<Integer>();

        for(int i=0;i<n;i++)

        {

             stack.push(a[i]);

        }

       ListIterator<Integer> lstIterator=stack.listIterator(stack.size());

       while(lstIterator.hasPrevious())

       {

           Integer res=lstIterator.previous();

           //what condition should i give so that it would print all the 

           elements except middle one.

           System.out.print(res+" ");   

       }

       System.out.println();

    }

  }

}

Do not insert the middle element of input array.

get the middle element index :

 int middle = a.length/2;

do not push the middle element in the stack:

Stack<Integer> stack=new Stack<Integer>();

for(int i=0;i<n;i++){

    if(i != middle)

      stack.push(a[i]);

}

Everything else looks okay. Just make sure to provide meaningful names to variables.

You can do this with using pop() method popping returns and removes the top element of the stack so that way you can create and fill a new stack with reverse order, don't need to reverse the iterator, have a look at the code below.

import java.util.ListIterator;

import java.util.Scanner;

import java.util.Stack;



class GFG {



  public static void main(String args) {

    Scanner s = new Scanner(System.in);

    //Define stacks here

    Stack<Integer> stack = new Stack<Integer>();

    Stack<Integer> new_stack = new Stack<Integer>();

    int test = s.nextInt();

    for (int t = 0; t < test; t++) {

      int n = s.nextInt();

      int a = new int[n];

      double middle = Math.ceil((double) n / 2);

      System.out.println("Middle is : " + middle);

      for (int i = 0; i < n; i++) {

        a[i] = s.nextInt();

      }



      // add elements to stack



      for (int i = 0; i < n; i++) {

        stack.push(a[i]);

      }



      //popping the elements of stack



      for (int j = 0; j < n; j++) {

        Integer element = stack.pop();

        if (j != middle -1) {

          new_stack.push(element);

        }

      }



      ListIterator<Integer> lstIterator = new_stack.listIterator(stack.size());

      while (lstIterator.hasNext()) {

        Integer res = lstIterator.next();

//what condition should i give so that it would print all the elements except middle one.

        System.out.print(res + " ");

      }

      System.out.println();

    }

  }

}