Compilare: user.cpp: In constructor ‘Hash::Hash(std::string)’: user.cpp:45: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘void solve()’: user.cpp:86: warning: comparison between signed and unsigned integer expressions user.cpp:88: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:102: warning: comparison between signed and unsigned integer expressions