HDOJ 3723 Delta Wave

网上抄的，Java的大数运算。
第一次提交JAVA的程序

Delta Wave

Time Limit: 6000/3000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 474    Accepted Submission(s): 152

Problem Description

A delta wave is a high amplitude brain wave in humans with a frequency of 1 – 4 hertz which can be recorded with an electroencephalogram (EEG) and is usually associated with slow-wave sleep (SWS).
-- from Wikipedia

The researchers have discovered a new kind of species called "otaku", whose brain waves are rather strange. The delta wave of an otaku's brain can be approximated by a polygonal line in the 2D coordinate system. The line is a route from point (0, 0) to (N, 0), and it is allowed to move only to the right (up, down or straight) at every step. And during the whole moving, it is not allowed to dip below the y = 0 axis.

For example, there are the 9 kinds of delta waves for N = 4:





Given N, you are requested to find out how many kinds of different delta waves of otaku.

 

Input

There are no more than 20 test cases. There is only one line for each case, containing an integer N (2 < N <= 10000)

 

Output

Output one line for each test case. For the answer may be quite huge, you need only output the answer module 10¹⁰⁰.

 

Sample Input

34

 

Sample Output

49

 

Source

2010 Asia Tianjin Regional Contest

 

Recommend

zhouzeyong

 

View Code

Problem : 3723 ( Delta Wave )     Judge Status : Accepted

RunId : 8303330    Language : Java    Author : CKboss

Code Render Status : Rendered By HDOJ Java Code Render Version 0.01 Beta

import java.math.BigInteger;

import java.util.Scanner;

public class Main

{

    public static void main(String[] args)

    {

        Scanner sc=new Scanner(System.in);

        BigInteger mod=BigInteger.TEN.pow(100);

        BigInteger sum=new BigInteger("0");

        BigInteger t=new BigInteger("0");

        while(sc.hasNext())

        {

            int n=sc.nextInt();

            sum=BigInteger.ONE;

            t=BigInteger.ONE;

            for(int k=1;k+k<=n;k++)

            {

                t=t.multiply(BigInteger.valueOf((n-2*k+1)*(n-2*k+2)))

                        .divide(BigInteger.valueOf(k*(k+1)));

                sum=sum.add(t);

            }

            System.out.println(sum.mod(mod));

        }

    }

}