Compilare: user.cpp: In function ‘int find_min_meeting_fuel(std::string)’: user.cpp:86:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int p1 = 0; p1 < word.size(); ++p1) ^ user.cpp:87:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int p2 = 0; p2 < word.size(); ++p2) ^ user.cpp:100:45: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int length = 1; length < word.size(); ++length) ^ user.cpp:101:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < word.size() - length; ++i) ^ user.cpp:102:52: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = i + length; j < word.size(); ++j) ^