Description
Given a string s containing only digits, return the lexicographically smallest string that can be obtained after swapping adjacent digits in s with the same parity at most once.
Digits have the same parity if both are odd or both are even. For example, 5 and 9, as well as 2 and 4, have the same parity, while 6 and 9 do not.
Example 1:
Input: s = "45320"
Output: "43520"
Explanation:
s[1] == '5' and s[2] == '3' both have the same parity, and swapping them results in the lexicographically smallest string.
Example 2:
Input: s = "001"
Output: "001"
Explanation:
There is no need to perform a swap because s is already the lexicographically smallest.
Constraints:
2 <= s.length <= 100sconsists only of digits.
Solution
Python3
class Solution:
def getSmallestString(self, s: str) -> str:
N = len(s)
res = list(s)
for i in range(1, N):
curr, prev = int(s[i]) % 2, int(s[i - 1]) % 2
if curr == prev and int(s[i]) < int(s[i - 1]):
res[i], res[i - 1] = s[i - 1], s[i]
break
return "".join(res)