Compilare: user.cpp: In function ‘void dfs()’: user.cpp:18:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<a[x].size()&&ok;i++) ^ user.cpp: In function ‘int main()’: user.cpp:35:24: warning: unused variable ‘ok’ [-Wunused-variable] int i,n,m,x,y;bool ok=1; ^