posts: union-find: fix union of same root

2024-06-27 13:16:44 +00:00 · 2024-06-27 13:16:44 +00:00 · 7873828c4c
parent adc514215c
commit 7873828c4c
1 changed files with 3 additions and 0 deletions
--- 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