You've got to find an optimal approach mathematically and logically speaking to not go through all numbers one by one

it's in the description

what is the variable 'n' even used for ?

It's just the number of multiplication it takes until the number we get is one digit.

The code doesn't work with large numbers. I used for loop. Suggestions ?

U have to return a pair of strings not a single one. U didnt read the description carefully. It sayz return odds and even indexes capitalized. Check again.

I am unsure if you have fixed you issue or not, but when I attempt to run your code, I get this: no viable conversion from 'std::string' (aka 'basic_string') to 'pair<std::string, std::string>' (aka 'pair<basic_string, basic_string >')
pair<string,string> actual = capitalize(s);

Why?

The reason for this is because your function, which you have named capitalize; does not match it's output with what the test requires. The test requires an output of std::pair<std::string, std::string>, not simple an std::string.

Large numbers aren't being handled properly, any help ?

If you know Josephus Permutation, it becomes easy ~

Thanks

Oh Okay!

that just means there are more tests in the section of the full test suite. Print the inputs to the console.

I pass my basic tests when I Test but during an attempt I get basic test wrong ?

Thanks for the feedback

Write a better code.