Compilare: user.cpp: In function ‘void dfs1(int)’: user.cpp:20:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<b[nod].size();i++){ ^ user.cpp: In function ‘int dfs(int, int)’: user.cpp:28:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<b[x].size();i++){ ^ user.cpp:31:1: warning: control reaches end of non-void function [-Wreturn-type] } ^