From 4a31531cf6ff7f938f785ce010b5a449edc91227 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E7=A7=BB=E5=8A=A8=E5=BC=80=E5=8F=91=E5=B0=8F=E5=86=89?=
 <510495266@qq.com>
Date: Mon, 15 Nov 2021 01:22:38 +0800
Subject: [PATCH] =?UTF-8?q?Update=20=E9=80=92=E5=BD=92.md?=
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---
 8 Algorithms Analysis/递归.md | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/8 Algorithms Analysis/递归.md b/8 Algorithms Analysis/递归.md
index 7f6b53f..0374c7f 100644
--- a/8 Algorithms Analysis/递归.md	
+++ b/8 Algorithms Analysis/递归.md	
@@ -233,6 +233,24 @@ public static LinkedNode mergeSeqLink(LinkedNode l1, LinkedNode l2){
 
 ```Java
 
+TreeNode lowestCommonAncestor(TreeNode root, TreeNode p, TreeNode q) {
+    // base case
+    if (root == null) return null;
+    if (root == p || root == q) return root;
+
+    TreeNode left = lowestCommonAncestor(root.left, p, q);
+    TreeNode right = lowestCommonAncestor(root.right, p, q);
+    // 情况 1
+    if (left != null && right != null) {
+        return root;
+    }
+    // 情况 2
+    if (left == null && right == null) {
+        return null;
+    }
+    // 情况 3
+    return left == null ? right : left;
+}
 ```