Hi.

I've submitted Problem C Round #395 (Div. 2). Why when I change these line

u=nodeColor.get(i);
v=nodeColor.get(a.get(i).get(j));
if (u!=v)

>>Full code

become

if ((Integer)nodeColor.get(i)!=(Integer)nodeColor.get(a.get(i).get(j)))

>>Full code

it get wrong answer?

Thanks!