1796. Second Largest Digit in a String

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.

풀이

var secondHighest = function(s) {
    let st = new Set();
    for(let i = 0; i < s.length; i++){
        if(s[i] === "0"){
            st.add(0);
        }
        if(parseInt(s[i])){
            st.add(parseInt(s[i]));
        }
    }
    if(st.size < 2) return -1;
    st.delete(Math.max(...st));
    return Math.max(...st);
};