Compilare: user.cpp: In function ‘int main()’: user.cpp:54:4: warning: value computed is not used [-Wunused-value] n - read_int(); ^ user.cpp:43:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("tetris2.in", "r", stdin); ^ user.cpp:44:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("tetris2.out", "w", stdout); ^ user.cpp: In function ‘int read_int()’: user.cpp:18:55: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] if (bpos >= DIM) fread(buf, 1, DIM, stdin), bpos = 0; ^ user.cpp:24:55: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] if (bpos == DIM) fread(buf, 1, DIM, stdin), bpos = 0; ^ user.cpp: In function ‘int main()’: user.cpp:55:2: warning: ‘n’ is used uninitialized in this function [-Wuninitialized] for (int i = 0; i < n; ++i, hash = 0){ ^