Compilare: user.cpp: In function ‘void read_data()’: user.cpp:18: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result user.cpp:22: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result user.cpp: In function ‘int main()’: user.cpp:65: warning: ‘sol’ may be used uninitialized in this function