Compilare: user.cpp: In function ‘int main()’: user.cpp:25: warning: format ‘%lf’ expects type ‘double’, but argument 2 has type ‘db’ user.cpp:25: warning: format ‘%lf’ expects type ‘double’, but argument 3 has type ‘db’ user.cpp:25: warning: format ‘%lf’ expects type ‘double’, but argument 4 has type ‘db’ user.cpp:18: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result