GenericStack

public class GenericStack<T> {
    private T S[];
    private int t; // top index in array

    public static final int CAPACITY = 100;
    @SuppressWarnings("unchecked")
    public GenericStack () {
        S = (T[]) new Object[CAPACITY];
        t = -1;
    }
    public void push (T x) {
        if(size()==100){
            System.out.println( "Stack is full." );
        }
        else{
            t = t + 1;
            S[t] = x;
        }
    }
    public T top () {
        if(isEmpty()){
            System.out.println("Stack is empty.");
        }
        return S[t];
    }
    public void pop () {
        if( !isEmpty()){
            t = t-1;
        }
        else{
            System.out.println ( "Stack is empty." );
        }
    }
    public boolean isEmpty () {
        if(size() == 0)
            return true;
        else
            return false;
    }
    public int size(){
        return t+1;
    }
}