在 C# 中查找节点的深度

public class TreeNode
{
    public int Val { get; set; }
    public TreeNode Left { get; set; }
    public TreeNode Right { get; set; }
}

public int GetDepth(TreeNode root, int target, int depth)
{
    if (root == null)
    {
        return -1;
    }

    if (root.Val == target)
    {
        return depth;
    }

    int leftDepth = GetDepth(root.Left, target, depth + 1);
    if (leftDepth != -1)
    {
        return leftDepth;
    }

    return GetDepth(root.Right, target, depth + 1);
}

TreeNode root = new TreeNode { Val = 1 };
root.Left = new TreeNode { Val = 2 };
root.Right = new TreeNode { Val = 3 };
root.Left.Left = new TreeNode { Val = 4 };
root.Left.Right = new TreeNode { Val = 5 };
root.Right.Left = new TreeNode { Val = 6 };
root.Right.Right = new TreeNode { Val = 7 };

int target = 5;
int depth = GetDepth(root, target, 0);
Console.WriteLine($"The depth of node {target} is {depth}.");

The depth of node 5 is 2.