Compilare: user.cpp: In function ‘int main()’: user.cpp:17:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1; i<s.size(); i++) ^ user.cpp: In function ‘void c()’: user.cpp:56:35: warning: suggest parentheses around assignment used as truth value [-Wparentheses] while(f=s.find('\n')!=string::npos) ^ user.cpp:60:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<s.size()-1; i++) ^