1796. 字符串中第二大的数字

1796. 字符串中第二大的数字

java:

class Solution {
    public int secondHighest(String s) {
        int max = -1;
        for (char ch : s.toCharArray()) {
            if (Character.isDigit(ch)) {
                max = Math.max(max, ch - '0');
            }
        }
        int ans = -1;
        for (char ch : s.toCharArray()) {
            if (Character.isDigit(ch)) {
                int a = ch - '0';
                if (a < max && a > ans) {
                    ans = a;
                }
            }
        }
        return ans;
    }
}

class Solution {
    public int secondHighest(String s) {
        int first = -1, second = -1;
        for (int i = 0; i < s.length(); i++) {
            char c = s.charAt(i);
            if (Character.isDigit(c)) {
                int num = c - '0';
                if (num > first) {  // 不断更新最大值
                    second = first;
                    first = num;
                } else if (num < first && num > second) {
                    second = num;
                }
            }
        }
        return second;
    }
}