Compilare: main.cpp: In function 'int main()': main.cpp:54:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0;i<Q[t].size();i++){ ~^~~~~~~~~~~~ main.cpp:29:32: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("car.in","r",stdin); ^ main.cpp:30:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("car.out","w",stdout); ^