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going/ | 2009-04-21 19:45 | - | ||
in0 | 2009-04-22 21:38 | 8 | ||
data1 | 2009-04-21 12:47 | 9 | ||
data2 | 2009-04-21 12:47 | 9 | ||
in1 | 2009-04-22 21:38 | 9 | ||
in2 | 2009-04-22 21:38 | 9 | ||
in4 | 2009-04-22 21:38 | 9 | ||
in3 | 2009-04-22 21:38 | 10 | ||
in1.out | 2009-04-22 21:38 | 21 | ||
out1 | 2009-04-22 21:38 | 21 | ||
in0.out | 2009-04-22 21:38 | 28 | ||
out0 | 2009-04-22 21:38 | 28 | ||
out3 | 2009-04-22 21:38 | 29 | ||
in4.out | 2009-04-22 21:38 | 30 | ||
out4 | 2009-04-22 21:38 | 30 | ||
in3.out | 2009-04-22 21:38 | 47 | ||
in2.out | 2009-04-22 21:38 | 69 | ||
out2 | 2009-04-22 21:38 | 69 | ||
Makefile | 2009-04-22 21:38 | 331 | ||
DTree.java | 2009-04-22 21:39 | 3.3K | ||
City.java | 2009-04-23 22:09 | 4.6K | ||
fsu0409contest.pdf | 2009-04-23 14:23 | 57K | ||
dijkstra.pdf | 2009-04-23 22:08 | 250K | ||
dijkstra.ppt | 2009-04-23 22:08 | 337K | ||
This is my attemnpt at a solution to Problem 6 of the spring 2009 FSU ACM local programming contest (see fsu0409contest.pdf). I picked this as an example of a problem that might be solved using Dijkstra's shortest-path algorithm.
Unfornately, the original problem statement has errors in it. The examples in the problem statement do not match the verbal description of the problem. To resole these inconsistencies, I first assumed that the intent was for the computations of neighbors be done mod 4 rather than mod N. Even at that, there was no path for the proposed example input. So, I assumed further that all edges of the graph are bidirectional. With that, I was able to match the judge's sample output for all but set in4. I believe that dataset is just wrong.
Regardless of the problems with the question and the Judge's sample data, this is still a valid application of Dijkstra's algorithm.
For fun, I tried coding solutions to this in several ways, including one using the standard java.utilities.PriorityQueue and one using a priority queue of my own (DTree.java).
The Java code of my solution using java.utilizies.PriorityQueue is in City.java.