Two Stacks in Array.cpp

#include<bits/stdc++.h>

using namespace std;

class twoStacks
{
    int *arr;
    int size;
    int top1, top2;
public:
   twoStacks(int n=100){size = n; arr = new int[n]; top1 = -1; top2 = size;}
 
   void push1(int x);
   void push2(int x);
   int pop1();
   int pop2();
};



int main()
{

    int T;
    cin>>T;
    while(T--)
    {
        twoStacks *sq = new twoStacks();

        int Q;
        cin>>Q;
        while(Q--){
        int stack_no;
        cin>>stack_no;
        int QueryType=0;
        cin>>QueryType;
        
        if(QueryType==1)
        {
            int a;
            cin>>a;
            if(stack_no ==1)
            sq->push1(a);
            else if(stack_no==2)
            sq->push2(a);
        }else if(QueryType==2){
        	if(stack_no==1)
            cout<<sq->pop1()<<" ";
            else if(stack_no==2)
            cout<<sq->pop2()<<" ";

        }
        }
        cout<<endl;
    }
}
// } Driver Code Ends

void twoStacks :: push1(int x)
{
    
    arr[++top1]=x;
}
   
/* The method push to push element into the stack 2*/
void twoStacks ::push2(int x)
{
    arr[--top2]=x;

}
   
/* The method pop to pop element from the stack 1 */
//Return the popped element
int twoStacks ::pop1()
{
    if(top1==-1) return -1;
    return arr[top1--];
}

/* The method pop to pop element from the stack 2 */
//Return the popped element
int twoStacks :: pop2()
{
    if(top2==size) return -1;
    return arr[top2++];
}