Tiny Stack

class MinStack {

    Node stack;
    int size;

    public void push(int data) {
        if (size == Integer.MAX_VALUE)
            throw new StackOverflowError();
        Node node = new Node(data);
        int min = Integer.MAX_VALUE;
        if (stack != null && stack.min != null)
            min = stack.min.data;
        if (data <= min)
            node.min = node;
        else
            node.min = stack.min;
        node.next = stack;
        stack = node;
        size++;
    }

    public void pop() {
        if (stack == null)
            throw new EmptyStackException();
        stack = stack.next;
        size--;
    }

    public int top() {
        if (stack == null)
            throw new EmptyStackException();
        return stack.data;
    }

    public int getMin() {
        if (stack == null)
            throw new EmptyStackException();
        if (stack.min == null)
            return 0;
        return stack.min.data;
    }

    class Node {

        int data;
        Node next;
        Node min;

        public Node(int data) {
            this.data = data;
        }
    }
}