OJ Board

I found where the problem.
it's in "336 - A Node Too Far"



1
10 11
10 0 10 1 10 2 12 1 10 0 10 1 10 2 0 0


1. when you get RE
possible reasons:
if you take all node in map, sometimes uva give unknown node as source node in test cases like 12 1
and if you try to get access with 12
your_map.at(12 ...