Compilare: user.cpp: In function ‘void read()’: user.cpp:40: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:43: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp: In function ‘void DFS(int, int)’: user.cpp:54: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int find(int)’: user.cpp:66: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘void insert(int)’: user.cpp:79: warning: comparison between signed and unsigned integer expressions