Converting a string char by char and copying it

I can use only <iostream> and <string> headers. (I am using C++)

I will read input from a text and convert it to lowercase type. I read the input and convert it to lowercase but i have a problem. It reads-converts everything properly but when I print it, there is no space between them. I should copy every "word" in a string and count the all words. How can I do it? Can you help me?