Compilare: user.cpp: In function ‘void solve()’: user.cpp:61:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<rs.size(); i++){ ^ user.cpp: In function ‘int main()’: user.cpp:78:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("lift.in", "rt", stdin); ^ user.cpp:79:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("lift.out", "wt", stdout); ^