UVa OJ Board

I think the main problem is the time limit. If you get WA, it's probably better to briefly describe your algorithm here. We might then be able to discuss and post some counterexamples.

Hello, I tried to solve 193 (and got AC in 0.01s), but I'm using some kind of probabilistic approach: I randomly select a node, remove it and its neighbours until there are no nodes left. I repeat this several times (100 is enough) to get the maximum node count. I know that this problem (Maximum Ind...

Thank you, got AC.

The wrong formula was a typing mistake in my post.

The main problem really was the rounding error! Stupid mistake.

Hello! Problem 10339 seems tricky to me. My idea to solve it was: When a (real) day has passed, the k-watch has counted (86400-k) seconds. The same holds for the m-watch and (86400-m) seconds. I calculate the number of (real) days, when the time difference between the two watches becomes 12 hours (4...

Just precalculate and store the factorials in an array. I'm using the same algorithm and get AC in 0.210 seconds.

What is your output for

1 2 2 3 3 1 4 5 0 0

it should be "not a tree". Such cases were a topic in the old message board long ago.

I don't know if there is any limit for the node numbers (except the limits of "integer"), so I stored the numbers in another array and did two lookups on every edge.

Hi, I did it the following way: - set the initial "result" value to n. - compute the lcm of every subset of divisors (except the empty one) - if the size of a subset it odd, subtract n/lcm from "result" - if it is even, add n/lcm to "result" Those operations can be done in an iteration loop, doing s...

Thank you!

Your algorithm seems quite correct to me, but I think there are some critical points:

In how many ways can 0$ be made up by 0 coins? 0 or 1?
In how many ways can more than 0$ be made up by 0 coins? 0 or 1?

The locations which are considered as "escaped" are those you marked with "A":

You may always change direction after moving one field.

http://www.acm.inf.ethz.ch/ProblemSetAr ... 1/acm91a.c

This is the "official" backtracking solution, which should make the output format clearer, but don't try it on Valladolid, it gets TLE.

After the input limit was set to 1000, I got some time problems, and - with BigNum and DP - I currently reach about 21 seconds. I'm using a sum of products to find the number. My question:

Is there an explicit formula to calculate those numbers?

I finally got AC - forgot to reset the sign flag in multiplication...

Thanks for the inspiration...

Hello World, I tried to get AC for that one several times, but no way... I'm currently using term splitting, scanning for "+" and "-" from the right (they associate left), afterwards for "*" from the right (dito) and for "**" (which I replaced before) from the left (right associative). I'm then call...