Compilare: user.cpp: In function ‘void read()’: user.cpp:27: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result user.cpp:29: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result user.cpp: In function ‘void tarjan(int)’: user.cpp:41: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘void write()’: user.cpp:75: warning: comparison between signed and unsigned integer expressions user.cpp:80: warning: comparison between signed and unsigned integer expressions user.cpp:82: warning: comparison between signed and unsigned integer expressions