Compilare: user.cpp: In function ‘int solve(std::string)’: user.cpp:11:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<s.size();++i) cntA+=(s[i]=='A'); ^ user.cpp:13:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(cntA<cntB) for(int i=0;i<s.size();++i) s[i]=char(((s[i]-'A')^1)+'A'); ^ user.cpp:14:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<s.size();++i) ^ user.cpp:22:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=start+1;i<start+1+s.size();++i) ss+=s[i%s.size()]; ^ user.cpp:26:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<s.size();++i) ^