谁能给我讲解下面代码的思想，特别感谢大神们，最好画个流程图

Question

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication1
{public class Stack
{
Entry top;
public void Push(object data)
{
top = new Entry(top, data); //进栈
}
public object Pop() //出栈
{
if (top == null) throw new InvalidOperationException();
object result = top.data;//获取堆栈顶端数据
top = top.next;
return result;
}
class Entry
{
public Entry next;
public object data;
public Entry(Entry next, object data)
{
this.next = next;
this.data = data;
}
}
class Stacktest
{
static void Main()
{
Stack S = new Stack();
S.Push(1); ///1进栈
S.Push(10); ///10进栈
S.Push(100); ///100进栈
Console.WriteLine(S.Pop()); ///出栈，输出100
Console.WriteLine(S.Pop());///出栈，输出10
Console.WriteLine(S.Pop());///出栈，输出1
Console.ReadKey();

        }
    }
}

}

Answer 1

就是堆栈，先进的后出，后进的先出。
和你堆叠一摞书类似，最后放上去的最先可以拿走，先放进去的压在下面，要等上面拿走了才能拿它。