Compilare: user.cpp: In function ‘int main()’: user.cpp:84:37: 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,buff_size, stdin); ^ user.cpp: In function ‘void read(int&)’: user.cpp:18:96: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] while(!isdigit(buff[pos])) if(++pos == buff_size) fread(buff, 1,buff_size, stdin), pos = 0; ^ user.cpp:23:73: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] if(++pos == buff_size) fread(buff, 1, buff_size, stdin), pos = 0; ^ user.cpp: In function ‘int main()’: user.cpp:97:28: warning: ‘maxij’ may be used uninitialized in this function [-Wmaybe-uninitialized] write_sol(maxii, maxij); ^ user.cpp:97:28: warning: ‘maxii’ may be used uninitialized in this function [-Wmaybe-uninitialized]