Compilare: user.cpp: In function ‘int dfs(int, int)’: user.cpp:39: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:62: warning: extended initializer lists only available with -std=c++0x or -std=gnu++0x user.cpp:63: warning: extended initializer lists only available with -std=c++0x or -std=gnu++0x