JAVA Backtracking || Worst Case but better understanding
\n`class Solution {\n    int totalcount = 0;\n    public int countVowelStrings(int n) {\n        char[]arr = new char[]{\'a\' , \'e\' , \'i\' , \'o\' , \'u\'};\
```\n`class Solution {\n    int totalcount = 0;\n    public int countVowelStrings(int n) {\n        char[]arr = new char[]{\'a\' , \'e\' , \'i\' , \'o\' , \'u\'};\n        dfs(arr , 0 , 0 , n);\n        return totalcount;\n    }\n    public void dfs(char[]arr , int start , int count , int size){\n        if(count == size){\n            totalcount ++;\n            return;\n        }\n        for(int i  = start ; i<5 ; i++){\n            count=count+1;\n            dfs(arr , i , count , size);\n            count=count-1;\n        }\n    }\n}\n```
['Java']