easy solution using (size -i)*(i+1) || C++
\nclass Solution {\npublic:\n    long long countVowels(string s) {\n        long long n = s.length();\n        long long sum = 0;\n        for (long long i = 0;
```\nclass Solution {\npublic:\n    long long countVowels(string s) {\n        long long n = s.length();\n        long long sum = 0;\n        for (long long i = 0; i < n; i++)\n            if (s[i] == \'a\' || s[i] == \'e\' || s[i] == \'i\' || s[i] == \'o\' || s[i] == \'u\')\n                sum += (n-i)*(i+1);\n        return sum;\n    }\n};\n```
['C']