// reverses the given stack using
// InsertAtBottom()
public static void Reverse(this StackUsingArray stack)
{
if (!stack.IsEmpty())
{
// Hold all items in Function
// Call Stack until we
// reach end of the stack
int popVal = stack.Pop();
stack.Reverse();
// Insert all the items held
// in Function Call Stack
// one by one from the bottom
// to top. Every item is
// inserted at the bottom
stack.InsertAtBottom(popVal);
}
}
// Below is a recursive function
// that inserts an element
// at the bottom of a stack.
private static void InsertAtBottom(this StackUsingArray stack, int element)
{
if (stack.IsEmpty())
{
stack.Push(element);
}
else
{
// All items are held in Function
// Call Stack until we reach end
// of the stack. When the stack becomes
// empty, the st.size() becomes 0, the
// above if part is executed and
// the item is inserted at the bottom
int value = stack.Pop();
stack.InsertAtBottom(element);
// push allthe items held
// in Function Call Stack
// once the item is inserted
// at the bottom
stack.Push(value);
}
}