Greatest English Letter in Upper and Lower Case
\nclass Solution {\n        public String greatestLetter(String s) {\n        boolean[] UpperCase = new boolean[26];\n        boolean[] LowerCase = new boolean[
```\nclass Solution {\n        public String greatestLetter(String s) {\n        boolean[] UpperCase = new boolean[26];\n        boolean[] LowerCase = new boolean[26];\n        char[] ch = s.toCharArray();\n        for (char c : ch) {\n            if (Character.isUpperCase(c)) {\n                UpperCase[c - \'A\'] = true;\n            } else {\n                LowerCase[c - \'a\'] = true;\n            }\n        }\n        for (int i = 25; i >= 0; i--) {\n            if (UpperCase[i] && LowerCase[i]) {\n                return (char) (i + \'A\') + "";\n\n            }\n        }\n        return "";\n    }\n}\n```
['Java']