Compilare: user.cpp: In function ‘double getDouble()’: user.cpp:26:67: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] if(++cnt >= buffer) fread(buff, buffer, 1, stdin), cnt = 0; ^ user.cpp:31:67: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] if(++cnt >= buffer) fread(buff, buffer, 1, stdin), cnt = 0; ^ user.cpp:33:63: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] if(++cnt >= buffer) fread(buff, buffer, 1, stdin), cnt = 0; ^ user.cpp:37:67: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] if(++cnt >= buffer) fread(buff, buffer, 1, stdin), cnt = 0; ^ user.cpp: In function ‘int main()’: user.cpp:52:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dstar.in", "r", stdin); ^ user.cpp:53:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dstar.out", "w", stdout); ^ user.cpp:54:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^