Compilare: user.cpp: In function ‘void dfs(int, int)’: user.cpp:20: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘void doo(int)’: user.cpp:33: warning: integer overflow in expression user.cpp:37: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:59: warning: unused variable ‘j’