[Leet Code] Second Largest Digit in a String

Leetcode: https://leetcode.com/problems/second-largest-digit-in-a-string/

Problem:

Given an alphanumeric string s, return the second largest numerical digit that appears in s, or -1 if it does not exist.

An alphanumeric string is a string consisting of lowercase English letters and digits.

Example 1:

Input: s = "dfa12321afd"
Output: 2
Explanation: The digits that appear in s are [1, 2, 3]. The second largest digit is 2.

Example 2:

Input: s = "abc1111"
Output: -1
Explanation: The digits that appear in s are [1]. There is no second largest digit.

Constraints:

• 1 <= s.length <= 500
• s consists of only lowercase English letters and/or digits.

Solution:

class Solution(object):
    def secondHighest(self, s):
        """
        :type s: str
        :rtype: int
        """
        answers = {}
        for i in s:
            if i.isdigit():
                answers[i] = 1
        
        if len(answers) >= 2:
            return sorted(answers, reverse=True)[1]
        else:
            return -1