diff --git a/problems/0116.填充每个节点的下一个右侧节点指针.md b/problems/0116.填充每个节点的下一个右侧节点指针.md
index 003ef75a..60ea9210 100644
--- a/problems/0116.填充每个节点的下一个右侧节点指针.md
+++ b/problems/0116.填充每个节点的下一个右侧节点指针.md
@@ -358,7 +358,84 @@ function connect(root: NodePro | null): NodePro | null {
 };
 ```
 
+```csharp
+//递归
+public class Solution {
+    public Node Connect(Node root) {
+        if (root == null) {
+            return null;
+        }
+        
+        ConnectNodes(root.left, root.right);
+        
+        return root;
+    }
 
+    private void ConnectNodes(Node node1, Node node2) {
+        if (node1 == null || node2 == null) {
+            return;
+        }
+
+        // 将左子节点的 next 指向右子节点
+        node1.next = node2;
+
+        // 递归连接当前节点的左右子节点
+        ConnectNodes(node1.left, node1.right);
+        ConnectNodes(node2.left, node2.right);
+
+        // 连接跨越父节点的两个子树
+        ConnectNodes(node1.right, node2.left);
+    }
+}
+
+
+// 迭代
+public class Solution
+{
+    public Node Connect(Node root)
+    {
+        Queue<Node> que = new Queue<Node>();
+
+        if (root != null)
+        {
+            que.Enqueue(root);
+        }
+
+        while (que.Count > 0)
+        {
+
+            var queSize = que.Count;
+            for (int i = 0; i < queSize; i++)
+            {
+                var cur = que.Dequeue();
+
+                // 当这个节点不是这一层的最后的节点
+                if (i != queSize - 1)
+                {
+                    // 当前节点指向下一个节点
+                    cur.next = que.Peek();
+                }
+                // 否则指向空
+                else
+                {
+                    cur.next = null;
+                }
+
+                if (cur.left != null)
+                {
+                    que.Enqueue(cur.left);
+                }
+                if (cur.right != null)
+                {
+                    que.Enqueue(cur.right);
+                }
+            }
+        }
+
+        return root;
+    }
+}
+```
 
 
 <p align="center">
diff --git a/problems/二叉树的递归遍历.md b/problems/二叉树的递归遍历.md
index 6dad6e56..b6dd7b6f 100644
--- a/problems/二叉树的递归遍历.md
+++ b/problems/二叉树的递归遍历.md
@@ -623,3 +623,4 @@ public void Traversal(TreeNode cur, IList<int> res)
 <a href="https://programmercarl.com/other/kstar.html" target="_blank">
   <img src="../pics/网站星球宣传海报.jpg" width="1000"/>
 </a>
+