【Java】hdu 4043

YY公式：1*3*5*(2n-1) / (n!*2^n)

java水过

import java.io.*;import java.math.*;import java.util.*;public class Main{public static void main(String[] args){Scanner cin = new Scanner(new BufferedInputStream(System.in));int t;t = cin.nextInt();int n;while((t--)!=0){BigInteger s1 = new BigInteger("1");BigInteger s2 = new BigInteger("1");n = cin.nextInt();int i;BigInteger tmp ;for(i=1;i<=n;i++){s1 = s1.multiply(BigInteger.valueOf(2*i-1));s2 = s2.multiply(BigInteger.valueOf(2*i));}tmp = s1.gcd(s2);System.out.println(s1.divide(tmp) + "/" + s2.divide(tmp));}}}