add 1796

fishercoder1534 · fishercoder1534 · commit 5a24e65d1d0a · 2021-03-20T11:44:44.000-07:00
diff --git a/README.md b/README.md
@@ -8,6 +8,7 @@ _If you like this project, please leave me a star._ &#9733;
 
 |  #  |      Title     |   Solutions   | Video  | Difficulty  | Tag                   
 |-----|----------------|---------------|--------|-------------|-------------
+|1796|[Second Largest Digit in a String](https://leetcode.com/problems/second-largest-digit-in-a-string/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1796.java) ||Easy|String|
 |1792|[Maximum Average Pass Ratio](https://leetcode.com/problems/maximum-average-pass-ratio/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1792.java) ||Medium|Heap|
 |1791|[Find Center of Star Graph](https://leetcode.com/problems/find-center-of-star-graph/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1791.java) ||Medium|Graph|
 |1790|[Check if One String Swap Can Make Strings Equal](https://leetcode.com/problems/check-if-one-string-swap-can-make-strings-equal/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1790.java) ||Easy|String|
diff --git a/src/main/java/com/fishercoder/solutions/_1796.java b/src/main/java/com/fishercoder/solutions/_1796.java
@@ -0,0 +1,23 @@
+package com.fishercoder.solutions;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.TreeSet;
+
+public class _1796 {
+    public static class Solution1 {
+        public int secondHighest(String s) {
+            TreeSet<Integer> set = new TreeSet<>();
+            for (char c : s.toCharArray()) {
+                if (Character.isDigit(c)) {
+                    set.add(Character.getNumericValue(c));
+                }
+            }
+            if (set.isEmpty() || set.size() == 1) {
+                return -1;
+            }
+            List<Integer> list = new ArrayList<>(set);
+            return list.get(list.size() - 2);
+        }
+    }
+}
