[c++] commented
\nclass Solution {\npublic:\n    int countVowelStrings(int n) {\n        vector<int>v(5,1); //[1,1,1,1,1] -> (a,e,i,o,u)\n        //for the n=2 ,consider this, 
```\nclass Solution {\npublic:\n    int countVowelStrings(int n) {\n        vector<int>v(5,1); //[1,1,1,1,1] -> (a,e,i,o,u)\n        //for the n=2 ,consider this, \n        // if starting is a, then the suffix can be any of the string in vector v from a\n        // i.e aa,ae,ai,ao,au\n        //for e, ee,ei,eo,eu and etc\n        \n        //for n=3\n        // beside a any of the 2 character string from vector starting from a can be placed,like:-\n        // a-> aaa,aae,.,.,aau\n        //     aee,aei,.,aeu\n        //     .\n        //     .\n        //     auu\n        \n        for(int i=2;i<=n;i++){\n            v[0]=v[0]+v[1]+v[2]+v[3]+v[4];\n            v[1]=v[1]+v[2]+v[3]+v[4];\n            v[2]=v[2]+v[3]+v[4];\n            v[3]=v[3]+v[4];\n            v[4]=v[4];\n        }\n        return v[0]+v[1]+v[2]+v[3]+v[4];\n    }\n};\n\n\n```
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