Compilare: user.cpp: In function ‘char gchar()’: user.cpp:16:38: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buff, buffer, 1, stdin); ^ user.cpp: In function ‘int main()’: user.cpp:175:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("hacker2.in", "r", stdin); ^ user.cpp:176:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("hacker2.out", "w", stdout); ^