Compilare: user.cpp: In function ‘int palindromeCreation(std::string&)’: user.cpp:19:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<S.size();i++) ^ user.cpp:26:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<aux.size();i++) ^ user.cpp:33:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i-len-1>=0&&i+len+1<aux.size()&&aux[i+len+1]==aux[i-len-1]) ^ user.cpp:41:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i-l-1>=0&&i+l+1<aux.size()&&aux[i-l-1]==aux[i+l+1]) ^ user.cpp:47:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<aux.size();i++) ^