http://acm.hdu.edu.cn/showproblem.php?pid=1023
1 //package dhsjdhjkh; 2 3 import java.util.*; 4 import java.io.*; 5 import java.math.BigInteger; 6 7 public class Main { 8 9 10 public static void main(String[] args) 11 { 12 int i; 13 BigInteger ans [] = new BigInteger[102]; 14 15 ans[0]= BigInteger.ONE; 16 ans[1]= BigInteger.ONE; 17 18 for(i=2;i<=100;i++) 19 ans[i]=BigInteger.ZERO; 20 // h(n)=h(n-1)*(4*n-2)/(n+1); 21 for(i=2;i<=100;i++){ 22 ans[i] = ans[i-1].multiply(BigInteger.valueOf(4*i-2)).divide(BigInteger.valueOf(i+1)); 23 24 } 25 26 27 28 Scanner cin = new Scanner(System.in); 29 30 while(cin.hasNext())//等价于!=EOF 31 { 32 int n = cin.nextInt();//读入一个大整数 33 34 // 35 System.out.println(ans[n]); 36 37 } 38 39 } 40 41 }