Compilare: user.cpp: In function ‘int main()’: user.cpp:96:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("pixels.in", "r", stdin); ^ user.cpp:97:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("pixels.out", "w", stdout); ^ user.cpp: In function ‘char nextch()’: user.cpp:26:30: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buff, 1, BMAX, stdin); ^