Compilare: user.cpp: In function ‘int main()’: user.cpp:24:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<p.size(); ++i) { ^ user.cpp:34:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=p.size(); i<s.size(); ++i) { ^