Welcome to Subscribe On Youtube
Formatted question description: https://leetcode.ca/all/1796.html
1796. Second Largest Digit in a String
Level
Easy
Description
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
Loop over s
and count the occurrences of all digits. Then loop over all digits backwards and find the second largest digit that has occurrence greater than 0. If such a digit exists, return the digit. Otherwise, return -1.
-
class Solution { public int secondHighest(String s) { int[] counts = new int[10]; int length = s.length(); for (int i = 0; i < length; i++) { char c = s.charAt(i); if (c >= '0' && c <= '9') counts[c - '0']++; } boolean flag = false; for (int i = 9; i >= 0; i--) { if (counts[i] > 0) { if (!flag) flag = true; else return i; } } return -1; } }
-
// OJ: https://leetcode.com/problems/second-largest-digit-in-a-string // Time: O(N) // Space: O(1) class Solution { public: int secondHighest(string s) { set<int> st; for (char c : s) { if (isdigit(c)) st.insert(c - '0'); } if (st.size() < 2) return -1; return *next(st.rbegin()); } };
-
class Solution: def secondHighest(self, s: str) -> int: a = b = -1 for c in s: if c.isdigit(): v = int(c) if v > a: a, b = v, a elif b < v < a: b = v return b ############ # 1796. Second Largest Digit in a String # https://leetcode.com/problems/second-largest-digit-in-a-string class Solution: def secondHighest(self, s: str) -> int: res = set(list(c for c in s if c.isdigit())) return sorted(list(res))[-2] if len(res) > 1 else -1