Compilare: main.cpp: In function 'int main()': main.cpp:44:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<marcei.size(); ++i) { ~^~~~~~~~~~~~~~ main.cpp:97:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<grupe.size(); ++i) { ~^~~~~~~~~~~~~ main.cpp:19:40: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen(ProblemName".in","r",stdin); ^ main.cpp:20:42: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen(ProblemName".out","w",stdout); ^