For string length you can use:
#include<string.h>
strlen(string);

Great!

Cool. But I think it's better to use "varible += something" over "varible = varible + something". It's my preference and you can do it as you want.

It's bad solution. I know...

This is not good solution. I have made a better one without list

I found flaw in my solution. It won't work if last symbol of string is '_' or '-'.