public object Pop()
{ //出栈
if (top == null)
{
throw new InvalidOperationException();
}
object result = top.data;
top = top.nextItem;//重新指定栈顶
return(result);
}
public object data; //栈顶数据
public StackForm(StackForm sNext, object sData)
{
this.nextItem = sNext;
this.data = sData;
}
StackForm top; //栈顶元素
public void Push(object data)
{ //入栈
//根据当前栈顶元素新构建一个新的栈顶，并将当前栈顶的NextItem指向原来的top
top = new StackForm(top, data);
}
