poj 2515 Birthday Cake

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poj2515
求 1 + 2^m +3^m + 4^m +...+N^m
from：曹如成 组合数学（p34）呵呵，还是java方便了。。。那就见代码了import java.io.*;import java.util.*;import java.math.*;public class Main {private static  int  NULL=0;    public static void main(String[] args) {        Scanner cin = new Scanner(System.in);        int i, j, t;        int m;        BigInteger N, b[][], c,ans,temp;        b = new BigInteger[102][102];        b[1][1]=BigInteger.ONE;        b[2][1]=BigInteger.ONE;        b[2][2]=BigInteger.valueOf(2);        for (i = 3; i <= 100; i++) {            b[i][1]=BigInteger.ONE;            for (j = 2; j <= i; j++) {                if((i-1)< j)b[i-1][j]=BigInteger.ZERO;                b[i][j]=b[i-1][j-1].add(b[i-1][j]);                b[i][j]=b[i][j].multiply(BigInteger.valueOf(j));            }        }        /*for(i=1;i<=100;i++)        {   for(j=1;j<=i;j++)                System.out.print(b[i][j]+" ");            System.out.println();        }*/        t=cin.nextInt();        while(cin.hasNext())        {            if(t==0)break;            t--;            N=cin.nextBigInteger();            m=cin.nextInt();            temp=N.add(BigInteger.ONE);            ans=BigInteger.ZERO;            for(i=1;i<=m;i++)            {                c=temp.multiply(N);                temp=c.divide(BigInteger.valueOf(i+1));                c=temp.multiply(b[m][i]);                ans=ans.add(c);                N=N.subtract(BigInteger.ONE);                if(N.compareTo(BigInteger.ZERO)==0) break;            }            System.out.println(ans);        }        // TODO code application logic here    }}