Compilare: main.cpp: In function 'void dfs(int, int)': main.cpp:34:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<v[x].size();i++) ~^~~~~~~~~~~~ main.cpp:45:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<v[x].size();i++) ~^~~~~~~~~~~~ main.cpp:30:11: warning: variable 'ok' set but not used [-Wunused-but-set-variable] int i,ok=0; ^~