Merge pull request codeharborhub#2722 from Hemav009/1796

Added solution to leetcode 1796

Author: ajay-dhangar

dsa-solutions/lc-solutions/1500-1599/1796-second-largest-digit-in-a-string.md

@@ -0,0 +1,124 @@
+---
+id: second-largest-digit-in-a-string
+title: Second Largest Digit in a String
+sidebar_label: 1796-Second Largest Digit in a String
+tags:
+  - Leet code
+description: "Solution to leetocde 1796"
+---
+
+## Problem Statement
+
+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.
+
+## Examples
+
+### 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.
+
+## Algorithm
+
+1. Extract all unique digits from the string.
+2. If the count of unique digits is less than 2, return -1.
+3. Convert the digits to integers and sort them in descending order.
+4. Return the second largest digit.
+
+## Python Code
+
+```python
+class Solution:
+    def secondHighest(self, s: str) -> int:
+        digits = {char for char in s if char.isdigit()}
+        if len(digits) < 2:
+            return -1
+        sorted_digits = sorted(map(int, digits), reverse=True)
+        return sorted_digits[1]
+```
+
+## C++ Code
+
+```cpp
+#include <string>
+#include <set>
+#include <algorithm>
+
+class Solution {
+public:
+    int secondHighest(std::string s) {
+        std::set<char> digits;
+        for (char ch : s) {
+            if (isdigit(ch)) {
+                digits.insert(ch);
+            }
+        }
+        if (digits.size() < 2) {
+            return -1;
+        }
+        auto it = digits.rbegin();
+        std::advance(it, 1);
+        return *it - '0';
+    }
+};
+```
+
+## Java Code
+
+```java
+import java.util.Set;
+import java.util.TreeSet;
+
+class Solution {
+    public int secondHighest(String s) {
+        Set<Character> digits = new TreeSet<>();
+        for (char ch : s.toCharArray()) {
+            if (Character.isDigit(ch)) {
+                digits.add(ch);
+            }
+        }
+        if (digits.size() < 2) {
+            return -1;
+        }
+        return Character.getNumericValue(((TreeSet<Character>) digits).lower(((TreeSet<Character>) digits).last()));
+    }
+}
+```
+
+## JavaScript Code
+
+```javascript
+/**
+ * @param {string} s
+ * @return {number}
+ */
+var secondHighest = function (s) {
+  let digits = new Set();
+  for (let char of s) {
+    if (/\d/.test(char)) {
+      digits.add(char);
+    }
+  }
+  if (digits.size < 2) {
+    return -1;
+  }
+  let sortedDigits = Array.from(digits)
+    .map(Number)
+    .sort((a, b) => b - a);
+  return sortedDigits[1];
+};
+```