Compilare: user.cpp: In function ‘void write_result()’: user.cpp:101:46: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<components[i].size();j++) write(components[i][j]),putChar(' '); ^ user.cpp: In function ‘void read(int&)’: user.cpp:22:96: 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:27:73: 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; ^