Compilare: user.cpp: In function ‘void input()’: user.cpp:19: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result user.cpp:23: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result user.cpp: In function ‘void DFS(int)’: user.cpp:36: warning: comparison between signed and unsigned integer expressions user.cpp:45: warning: comparison between signed and unsigned integer expressions