✅C++ Solution | No hashmap low storage | Easy
\nclass Solution {\npublic:\n    string greatestLetter(string s) {\n        int low[26]={0},up[26]={0};\n        for(auto i:s){\n            if(isalpha(i)){\n  
```\nclass Solution {\npublic:\n    string greatestLetter(string s) {\n        int low[26]={0},up[26]={0};\n        for(auto i:s){\n            if(isalpha(i)){\n                if(islower(i)){\n                    low[i-97]++;\n                }\n                else{\n                    up[i-65]++;\n                }\n            }\n        }\n        for(int i=25;i>=0;i--){\n            string c;\n            c+=(char)i+65;\n            if(up[i]>0 && low[i]>0)\n                return c;\n        }\n        return "";\n    }\n};\n```
['C', 'C++']