Compilare: user.cpp: In function ‘int main()’: user.cpp:180:24: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d\n",&n); ^ user.cpp:184:34: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d %d\n",&x,&y); ^ user.cpp:191:24: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d\n",&k); ^ user.cpp: In member function ‘void query_t::read()’: user.cpp:17:48: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%c %d %d %d\n",&c,&u,&v,&val); ^