implementation of stack

//program is implemented by shadab khan

#include<conio.h>

#include<iostream.h>

#include<process.h>

void main()

{

            int stack[150],top,n,i,max_stack,choice,element,n_pop;

            max_stack=150;

            cout<<"How many elements are in the stack: ";

            cin>>n;

            cout<<"Enter "<<" elements.\n";

            for(top=0;top>stack[top];top++)

            {

                        cin>>stack[top];

            }

            cout<<"\nStack is implemented.\nThe stack is\n";

            for(i=top-1;i>=0;i--)

                        cout<<"   ";

            getch();

            while(1)

            {

                        clrscr();

                        cout<<"1: PUSH\n2: POP\n3: Display Stack\n4: Exit\nEnter your choice: ";

                        cin>>choice;

                        switch(choice)

                        {

                                    case 1:     //  PUSH

                                                cout<<"\nPUSH OPERATION\n";

                                                if(top>=max_stack)

                {

                                                            cout<<"Stack is full!";

                                                            getch();

                                                            break;

                                                }

                                                cout<<"Enter an element: ";

                                                cin>>element;

                                                stack[top]=element;

                top++;

                                                cout<<"Item Inserted!";

                                                getch();

                                                break;

                                    case 2:             // POP

                                                cout<<"POP OPERATION\n";

                                                if(top<0)

                                                {

                                                            cout<<"Stack is empty";

                                                            getch();

                                                            break;

                                                }

                                                cout<<"How many elements you want to pop: ";

                cin>>n_pop;

                                                if(n_pop>top)

                                                {

                                                            cout<<"\nError!\nStack is small.";

                                                            getch();

                   break;

                                                }

                                                top=top-n_pop;

                                                cout<<"Items POPed";

                                                getch();

                                                break;

                                    case 3:       //  Display

                                                cout<<"\The stack is\n";

                                                for(i=top-1;i>=0;i--)

                                                            cout<< stack[i] <<"   ";

                                                getch();

                                                break;

                                    case 4:

                                                exit(0);

                                                getch();

                                    default:

                                                cout<<"RE-enter your choice!";

                        }          // End of switch

            }                      // End of while

            getch();

}