From 7aef42def84ef94f198eedd85a946130319264da Mon Sep 17 00:00:00 2001
From: eeee0717 <chentao020717Work@outlook.com>
Date: Tue, 28 Nov 2023 10:17:25 +0800
Subject: [PATCH] =?UTF-8?q?Update=200098.=E9=AA=8C=E8=AF=81=E4=BA=8C?=
 =?UTF-8?q?=E5=8F=89=E6=90=9C=E7=B4=A2=E6=A0=91=EF=BC=8C=E6=B7=BB=E5=8A=A0?=
 =?UTF-8?q?C#=E7=89=88?=
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---
 problems/0098.验证二叉搜索树.md | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/problems/0098.验证二叉搜索树.md b/problems/0098.验证二叉搜索树.md
index 184060a5..319ad1aa 100644
--- a/problems/0098.验证二叉搜索树.md
+++ b/problems/0098.验证二叉搜索树.md
@@ -791,6 +791,20 @@ impl Solution {
     }
 }
 ```
+### C#
+```C#
+// 递归
+public long val = Int64.MinValue;
+public bool IsValidBST(TreeNode root)
+{
+    if (root == null) return true;
+    bool left = IsValidBST(root.left);
+    if (root.val > val) val = root.val;
+    else return false;
+    bool right = IsValidBST(root.right);
+    return left && right;
+}
+```
 
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