Compilare: user.cpp: In function ‘int main()’: user.cpp:47: warning: format ‘%ld’ expects type ‘long int’, but argument 2 has type ‘int’ user.cpp:54: warning: format ‘%ld’ expects type ‘long int’, but argument 3 has type ‘int’ user.cpp:13: warning: unused variable ‘o’ user.cpp:16: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result user.cpp:21: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result