hdu 4762 公式 java

n/(n)^(m-1)

 import java.io.*;
 import java.math.*;
 import java.util.*;

 public class Main {
     static BigInteger gcd(BigInteger a,BigInteger b)
     {
         if(b.equals(BigInteger.ZERO))return a;
         else return gcd(b,a.mod(b));
     }
     public static void main(String arg[])
     {
         int T;
         int n,m;
         Scanner cin = new Scanner(System.in);
         T = cin.nextInt();
         while( T > 0 )
         {
             m = cin.nextInt();
             n = cin.nextInt();
             BigInteger tmp1 = BigInteger.valueOf(n);
             BigInteger tmp2 = BigInteger.valueOf(m).pow(n-1);
             BigInteger tt = gcd(tmp1,tmp2);
             tmp1 = tmp1.divide(tt);
             tmp2 = tmp2.divide(tt);
             System.out.println(tmp1+"/"+tmp2);
             T--;
         }
     }
 }