Update0108.将有序数组转换为二叉搜索树，添加C#

problems/0108.将有序数组转换为二叉搜索树.md

@@ -530,6 +530,23 @@ impl Solution {
     }
 }
 ```
+### C#
+```csharp
+// 递归
+public TreeNode SortedArrayToBST(int[] nums)
+{
+    return Traversal(nums, 0, nums.Length - 1);
+}
+public TreeNode Traversal(int[] nums, int left, int right)
+{
+    if (left > right) return null;
+    int mid = left + (right - left) / 2;
+    TreeNode node = new TreeNode(nums[mid]);
+    node.left = Traversal(nums, left, mid - 1);
+    node.right = Traversal(nums, mid + 1, right);
+    return node;
+}
+```
 
 
 <p align="center">