From 00eacff816e458cadb4442e7b2ec596e6bce1a88 Mon Sep 17 00:00:00 2001
From: Yitzchak Scott-Thoennes <sthoenna@gmail.com>
Date: Sun, 27 Jul 2025 21:03:54 -0400
Subject: challenge 331: fix task2 solutions

---
 challenge-331/ysth/python/ch-2.py | 25 ++++++++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

(limited to 'challenge-331/ysth/python')

diff --git a/challenge-331/ysth/python/ch-2.py b/challenge-331/ysth/python/ch-2.py
index 6d0f7c80e4..a87815fd24 100644
--- a/challenge-331/ysth/python/ch-2.py
+++ b/challenge-331/ysth/python/ch-2.py
@@ -3,7 +3,30 @@ import regex
 from itertools import batched
 
 def buddy_strings(string1: str, string2: str) -> bool:
-    return True if regex.fullmatch(regex.escape(string1)+'{1<=s<=1}', string2) else False
+    if len(string1) != len(string2):
+        return False
+    swaps = 0
+    pair_exists: bool = False
+    previous_character1: str
+    previous_character2: str
+    for i in range(len(string1)):
+        character1: str = string1[i]
+        character2: str = string2[i]
+        if swaps == 1:
+            # second character of swap
+            if previous_character2 != character1 or character2 != previous_character1:
+                return False
+            swaps = 2
+        elif string1[i] != string2[i]:
+            # starting the first swap
+            if swaps > 0:
+                return False
+            previous_character1 = character1
+            previous_character2 = character2
+            swaps = 1
+        pair_exists = pair_exists or i > 0 and string1[i-1] == string1[i]
+
+    return pair_exists and swaps == 0 or swaps == 2
 
 def main() -> None:
     inputs: list[str] = sys.argv[1:]
-- 
cgit