c# 用非递归的写法实现递归

最近写代码碰到了一个bug，就是递归次数太多爆堆栈了，然后就写了一个递归工具来解决这个问题。

using System;
using System.Collections.Generic;/// <summary>
/// 递归工具
/// </summary>
public static class RecursionTool
{//递归方式 1 >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>/// <summary>/// 树节点接口/// </summary>public interface ITreeNode{/// <summary>/// 访问标记/// </summary>bool Visited { get; set; }/// <summary>/// 子节点/// </summary>List<ITreeNode> Children { get; set; }}/// <summary>/// 递归算法的非递归实现/// 以节点树的方式递归/// </summary>public static (bool result, object args) Recursive(IEnumerable<ITreeNode> rootNodes,Func<ITreeNode, (bool result, object args)> handleNode){var stack = new Stack<ITreeNode>();foreach (var item in rootNodes){item.Visited = false;stack.Push(item);}while (stack.Count > 0){var rootNode = stack.Peek();//没访问过，且有子节点时if (rootNode.Visited == false && rootNode.Children != null && rootNode.Children.Count > 0){rootNode.Visited = true;//把子节点全部入栈foreach (var item in rootNode.Children){item.Visited = false;stack.Push(item);}}//访问处理根节点else{rootNode = stack.Pop();rootNode.Visited = false;if (handleNode != null){var tuple = handleNode(rootNode);if (tuple.result){return tuple;}}}}return (false, null);}//递归方式 2 >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>/// <summary>/// 递归状态/// </summary>public enum ERecursiveState{Finish,Next,Skip,}/// <summary>/// 递归算法的非递归实现/// 根据回调里的逻辑递归/// </summary>public static (bool result, object args) Recursive<TNode>(IEnumerable<TNode> rootNodes,Func<TNode, (ERecursiveState state, bool result, object args, IEnumerable<TNode> nexts)> handleNode){var stack = new Stack<TNode>();foreach (var item in rootNodes){stack.Push(item);}while (stack.Count > 0){var rootNode = stack.Pop();if (handleNode != null){var tuple = handleNode(rootNode);switch (tuple.state){case ERecursiveState.Finish:return (tuple.result, tuple.args);case ERecursiveState.Next:{if (tuple.nexts != null){foreach (var item in tuple.nexts){stack.Push(item);}}}break;}}}return (false, null);}}

也很久没写文章了，顺手记录一下。