Added solution for https://leetcode.com/problems/buddy-strings/

Author: fspv

l33tcode/buddy-strings.py

@@ -0,0 +1,31 @@
+class Solution:
+    def buddyStrings(self, A: str, B: str) -> bool:
+        if len(A) != len(B):
+            return False
+
+        first, second = -1, -1
+        replacements = 0
+        pos = 0
+
+        while pos < len(A):
+            if A[pos] != B[pos]:
+                replacements += 1
+
+                if replacements > 2:
+                    return False
+
+                first, second = second, pos
+
+            pos += 1
+
+        if replacements > 2:
+            return False
+        elif replacements == 2:
+            if (A[first], A[second]) != (B[second], B[first]):
+                return False
+        elif replacements == 1:
+            return False
+        else:
+            return len(set(A)) != len(A)
+
+        return True