From d8c1f83711fd0da476e793dcf78a0d90a53e5de8 Mon Sep 17 00:00:00 2001
From: user <user@localhost>
Date: Wed, 29 Jul 2026 21:12:36 +0400
Subject: [PATCH] fix: handle odd-length palindromes by preserving middle
 character

---
 3518/solution.cpp | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/3518/solution.cpp b/3518/solution.cpp
index 45fbf10..2345852 100644
--- a/3518/solution.cpp
+++ b/3518/solution.cpp
@@ -9,6 +9,7 @@ public:
   std::string smallestPalindrome(std::string s, int k) {
 
     std::string half = s.substr(0, s.size() / 2);
+    char middle = (s.size() % 2 == 1) ? s[s.size() / 2] : '\0';
 
     std::ranges::sort(half);
 
@@ -28,11 +29,15 @@ public:
     }
 
     auto it = permutations.begin();
-    advance(it, k - 1);
+    std::advance(it, k - 1);
 
     std::string mirroredHalf = *it;
     std::ranges::reverse(mirroredHalf);
 
+    if (middle != '\0') {
+      return *it + std::string(1, middle) + mirroredHalf;
+    }
+
     return *it + mirroredHalf;
   }
 };