Hello all! I was trying to solve this problem from the recent APAC contest: https://code.google.com/codejam/contest/10214486/dashboard
I think this problem can be solved by dijkstra's shortest path algorithm. I precompute the minimum time taken from the source for every value of S so that the queries can be answered in constant time.
Here's my code: http://ideone.com/cle94b
I don't see why I am getting a WA.
Any help is appreciated. Thanks!