2022-06-19 update: added "Greatest English Letter in Upper and Lower Case"

Author: fartem

src/main/java/com/smlnskgmail/jaman/leetcodejava/easy/GreatestEnglishLetterInUpperAndLowerCase.java

@@ -0,0 +1,31 @@
+package com.smlnskgmail.jaman.leetcodejava.easy;
+
+// https://leetcode.com/problems/greatest-english-letter-in-upper-and-lower-case/
+public class GreatestEnglishLetterInUpperAndLowerCase {
+
+    private final String input;
+
+    public GreatestEnglishLetterInUpperAndLowerCase(String input) {
+        this.input = input;
+    }
+
+    public String solution() {
+        char[] upper = new char[128];
+        char[] lower = new char[128];
+        for (int i = 0; i < input.length(); i++) {
+            char curr = input.charAt(i);
+            if (Character.isUpperCase(curr)) {
+                upper[curr]++;
+            } else {
+                lower[curr]++;
+            }
+        }
+        for (char c = 'Z'; c >= 'A'; c--) {
+            if (upper[c] > 0 && lower[Character.toLowerCase(c)] > 0) {
+                return String.valueOf(c);
+            }
+        }
+        return "";
+    }
+
+}

src/test/java/com/smlnskgmail/jaman/leetcodejava/easy/GreatestEnglishLetterInUpperAndLowerCaseTest.java

@@ -0,0 +1,17 @@
+package com.smlnskgmail.jaman.leetcodejava.easy;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class GreatestEnglishLetterInUpperAndLowerCaseTest {
+
+    @Test
+    public void defaultTest() {
+        assertEquals(
+                "E",
+                new GreatestEnglishLetterInUpperAndLowerCase("lEeTcOdE").solution()
+        );
+    }
+
+}