OJ Board

I don't have a suggestion. I just wanted to thank you guys for the awesome feature of having solved and attempted problems coloured on the problem lists. It's really great, and I'm finding it useful already.

import java.io.*;
import java.util.*;
import java.text.*;

class Main {
public static void main (String args[]) throws IOException {
Scanner in = new Scanner(System.in);
DecimalFormat f = new DecimalFormat();
f.setMaximumFractionDigits(4);
f.setMinimumFractionDigits(4);
while (in.hasNext ...

I just wanted to say that the new site is great. I love the new Java support.

I have one suggestion, though. It would be nice to be able to view which problems we have solved on our user pages, like before. Another possible feature could be displaying something to indicate which problems we have ...

BigInt arr[] = new BigInt[301];
arr[0] = new BigInt(1);
for (int k=0; k<arr.length-1; k++) {
int top = (((2*k)+1)*((2*k)+2));
int bottom = (k+2);

arr[k+1] = arr[k].multiply(new BigInt(top));
arr[k+1] = arr[k+1].divide(new BigInt(bottom));

}

I think your algorithm is correct. I dont ...

I'm pretty what I have is correct, because the Catalan numbers correspond to the number of unlabeled binary trees. In the case of 10007, the trees are labelled, so the formula is multiplied by n!.

(2n)!/(n+1)! is the formula, if I am not mistaken.

Thanks again for the response. I'm still completely puzzled as to why I continue to get WA.

Do you see anything wrong with this algorithm? (it's in java and uses a BigInt class that I found on the java forum, but I think it's fairly straight forward)

BigInt arr[] = new BigInt[301];
arr[0] = new ...

here is the output of my AC program for input 300:
13737807510976206042952273897263258508116975599604959518836124365862819224972658
54247030784146639904262298233057468287928668494180243215174601311778665118426704
17171885915385919843693603797986405860478580069565298906600371579310154166721548 ...

I'm having a hard time understanding why I'm getting WA. I'm computing all of the values up to 300 dynamically, sticking them into an array, and calling the appropriate values when requested.

The correct value for n=300 is going to work out to 600!/301!, right?
I've compared that value worked out ...

Can someone post some input and output?
My program passes the sample input, but I keep getting wrong answer.

Thanks.