Compilare: user.cpp: In function ‘std::vector<int> KMP(std::string, std::string)’: user.cpp:22:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (pos_input < input.size()) { ^ user.cpp:23:99: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (pos_substr != -1 && (substr[pos_substr] != input[pos_input] || pos_substr == substr.size())) pos_substr = positions.at(pos_substr); ^ user.cpp:26:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (pos_substr == substr.size()) result.push_back(pos_input - pos_substr); ^