Compilare: user.cpp: In function ‘int is(std::string)’: user.cpp:13:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<s.size(); ++i) ++cnt[s[i]-'A']; ^ user.cpp:14:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(cnt[0]<cnt[1]) for(int i=0; i<s.size(); ++i) s[i]=(1-(s[i]-'A'))+'A'; ^ user.cpp:15:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(p=0; p<s.size(); ++p) if(s[p]=='B') break; ^ user.cpp:16:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(p==s.size()) return 1; ^ user.cpp:17:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=p+1; i<s.size()+p+1; ++i) n+=s[i%s.size()]; ^ user.cpp:21:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<n.size(); ++i) ^ user.cpp:31:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<v.size(); ++i) ^