Buddy Strings LeetCode solution in Python

1
# Runtime: 54 ms (Top 48.33%) | Memory: 14.1 MB (Top 96.59%)
2

3
from collections import Counter
4

5

6
class Solution:
7
    def buddyStrings(self, s: str, goal: str) -> bool:
8
        if len(s) != len(goal):
9
            return False
10
        diffCharactersCount = 0
11
        diffCharactersInS = []
12
        diffCharactersInGoal = []
13
        for i in range(len(s)):
14
            if s[i] != goal[i]:
15
                diffCharactersCount += 1
16
                diffCharactersInS.append(s[i])
17
                diffCharactersInGoal.append(goal[i])
18
        if diffCharactersCount == 2:
19
            # if there are only 2 different characters, then they should be swappable
20
            if (diffCharactersInS[0] == diffCharactersInGoal[1]) and (
21
                diffCharactersInS[1] == diffCharactersInGoal[0]
22
            ):
23
                return True
24
            return False
25
        elif diffCharactersCount == 0:
26
            # if there is atleast one repeating character in the string then its possible for swap
27
            counts = Counter(s)
28
            for k, v in counts.items():
29
                if v > 1:
30
                    return True
31
        # if different characters count is not 2 or 0, then it's not possible for the strings to be buddy strings
32
        return False