Compilare: user.cpp: In function ‘void df(int, int)’: user.cpp:17: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:53: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result user.cpp:55: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result user.cpp:58: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result