本文介绍了在枚举时插入队列的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!

问题描述

我想使用队列对树进行广泛的首次搜索

I want to do a breadth first search of a tree using a Queue

var q = new Queue<T>();

q.Enqueue(Root);

foreach(T root in q)
{
  foreach(T t in root.Children)
    q.Enqueue(t);
}

然而,我得到一个在枚举器被实例化之后被修改的集合。

However I get a "Collection was modified after the enumerator was instantiated." Exception.

有没有C#类型,我可以这样做?

Is there a C# type that I can do this with?

编辑:一点点阅读让我的东西,我可能会这样做完全错误。

a little reading make me thing I might be doing this totally wrong.

有没有办法使用foreach从队列中排队?

Is there a way to use a foreach to dequeue from a Queue?

这样做是丑的(OMHO)

this works but is ugly (OMHO)

var q = new Queue<T>();

q.Enqueue(Root);

while(q.Count > 0)
{
  T root = q.Dequeue();
  foreach(T t in root.Children)
    q.Enqueue(t);
}


推荐答案

你不能枚举过一个IEnumerable并同时更改相同的IEnumerable。我不认为有一个C#集合将允许这个。

You can't enumerate over an IEnumerable and change the same IEnumerable at the same time. I don't think there is a C# Collection that will allow this.

这篇关于在枚举时插入队列的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!

09-03 10:22