From 7873828c4c523f98104767a9f1fc70e69611e00f Mon Sep 17 00:00:00 2001
From: Bruno BELANYI <bruno@belanyi.fr>
Date: Thu, 27 Jun 2024 13:16:44 +0000
Subject: [PATCH] posts: union-find: fix union of same root

---
 content/posts/2024-06-24-union-find/index.md | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/content/posts/2024-06-24-union-find/index.md b/content/posts/2024-06-24-union-find/index.md
index 2fe1570..7c9435c 100644
--- a/content/posts/2024-06-24-union-find/index.md
+++ b/content/posts/2024-06-24-union-find/index.md
@@ -142,6 +142,9 @@ _approximate_ height, we can keep the trees balanced when merging them.
 def union(self, lhs: int, rhs: int) -> int:
     lhs = self.find(lhs)
     rhs = self.find(rhs)
+    # Bail out early if they already belong to the same set
+    if lhs == rhs:
+      return lhs
     # Always keep `lhs` as the taller tree
     if (self._rank[lhs] < self._rank[rhs])
         lhs, rhs = rhs, lhs