Implement stack using array

Implement a Stack using Array. Your task is to complete the functions below.

Input Format:
The first line of the input contains an integer 'T' denoting the number of test cases. Then T test cases follow.
First line of each test case contains an integer Q denoting the number of queries . 
A Query Q is of 2 Types:
(i) 1 x   (a query of this type means  pushing 'x' into the stack)
(ii) 2     (a query of this type means to pop element from stack and print the poped element)
The second line of each test case contains Q queries seperated by space.

Output Format:
The output for each test case will  be space separated integers having -1 if the stack is empty else the element poped out from the stack .

Your Task:
You are required to complete two methods push which take one argument an integer 'x' to be pushed into the stack  and pop which returns a integer poped out from the stack.

Constraints:
1 <= T <= 100
1 <= Q <= 100
1 <= x <= 100

Example:
Input:
1
5
1 2 1 3 2 1 4 2
4
2 1 4 1 5 2  

Output:
3 4
-1 5

Explanation:
In the first test case for query 
1 2    the stack will be {2}
1 3    the stack will be {2 3}
2       poped element will be 3 the stack will be {2}
1 4    the stack will be {2 4}
2       poped element will be 4

CODE:


/*Please note that it's Function problem i.e.
you need to write your solution in the form of Function(s) only.
Driver Code to call/invoke your function is mentioned above.*/

/* 
The structure of the class is
class Stack_using_array {
     int top;
	 int arr[]=new int[1000];
    Stack_using_array()
	{
		top = -1;
	}
 */
class GfG
{
	/* The method push to push element into the stack */
	void push(int a, Stack_using_array ob)
			{
				//Your code
				if(ob.top<1000){
				ob.top++;
				ob.arr[ob.top]=a;}
			} 
         /*The method pop which return the element poped out of the stack*/
		int pop(Stack_using_array ob)
		{
			//Your code
			int x=-1;
			if(ob.top!=-1){
			x=ob.arr[ob.top];
			ob.top--;}
			return x;
		} 
}