👀 Views: 3 💬 Answers: 1 📅 Created: 2025-06-06

c# recursive tree stackoverflowexception C#

I'm trying to configure I'm working on a personal project and After trying multiple solutions online, I still can't figure this out... I'm encountering a `StackOverflowException` when trying to implement a recursive method to traverse a tree structure in C#. My tree consists of nodes that can have multiple children, and I'm trying to traverse the tree to collect values in a list. Below is the relevant code: ```csharp public class TreeNode { public int Value { get; set; } public List<TreeNode> Children { get; set; } = new List<TreeNode>(); } public class Tree { public TreeNode Root { get; set; } public List<int> Traverse(TreeNode node) { var values = new List<int>(); CollectValues(node, values); return values; } private void CollectValues(TreeNode node, List<int> values) { if (node == null) return; values.Add(node.Value); foreach (var child in node.Children) { CollectValues(child, values); } } } ``` When I call the `Traverse` method, I sometimes get `System.StackOverflowException`, especially when the tree is deep or if there are cycles in the tree structure (where a child node references its parent). I’ve added checks for null nodes, but I suspect that the issue arises from having cycles in the tree. I've tried implementing a HashSet to keep track of visited nodes in order to prevent infinite recursion, but I’m not sure how to effectively integrate that into my current recursive method. Here's what I attempted: ```csharp private void CollectValues(TreeNode node, List<int> values, HashSet<TreeNode> visited) { if (node == null || visited.Contains(node)) return; visited.Add(node); values.Add(node.Value); foreach (var child in node.Children) { CollectValues(child, values, visited); } } ``` I call it like this: ```csharp var tree = new Tree(); // Assume tree is populated var result = tree.Traverse(tree.Root); ``` However, I still encounter the same `StackOverflowException`. Can anyone suggest best practices for handling tree traversal in C#, especially in the context of avoiding stack overflows due to deep recursion or cycles? Has anyone else encountered this? I'm working on a application that needs to handle this. Any ideas what could be causing this? Could this be a known issue?