Compilare: user.cpp: In function ‘int calc(int, int)’: user.cpp:41:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<vx.size();++i){ ^ user.cpp: In function ‘int main()’: user.cpp:82:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("test.in","r",stdin); ^ user.cpp:83:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("joc2.out","w",stdout); ^