Compilare: user.cpp: In member function ‘bool comparator::operator()(int, int)’: user.cpp:37:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < tpl[1].vecini.size(); ++i){ ^ user.cpp:43:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j = 0; j < tpl[1].vecini.size(); ++j){ ^ user.cpp: In function ‘int main()’: user.cpp:87:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dijkstra.in", "rt", stdin); ^ user.cpp:88:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dijkstra.out", "wt", stdout); ^