Compilare: user.cpp: In function ‘int main()’: user.cpp:32:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("zeroc.in","r",stdin); ^ user.cpp:33:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("zeroc.out","w",stdout); ^ user.cpp: In function ‘void Next()’: user.cpp:142:44: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] std::fread(s, 1, Lim, stdin), u = 0; ^