Compilare: user.cpp: In function ‘void df(int, int, int)’: user.cpp:15:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<a[nod].size();i++){ ^ user.cpp:16:4: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if(a[nod][i]!=tata) ^ user.cpp: In function ‘void dfs(int, int)’: user.cpp:30:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<a[nod].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:50:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int h=0;h<a[i].size();h++) ^