Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:45: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘void prepare()’: user.cpp:59: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘void dfs2(int)’: user.cpp:77: warning: comparison between signed and unsigned integer expressions user.cpp:85: warning: comparison between signed and unsigned integer expressions user.cpp:91: warning: comparison between signed and unsigned integer expressions user.cpp:94: warning: comparison between signed and unsigned integer expressions user.cpp:76: warning: unused variable ‘j’ user.cpp:76: warning: unused variable ‘vec2’