3181.txt

北大ACM题目例程 详细的解答过程 程序实现 算法分析

Source

Problem Id:3181  User Id:fzk 
Memory:3632K  Time:1965MS
Language:Java  Result:Accepted

Source 

import java.math.BigInteger;
import java.util.*;


public class Main
{
    public static void main(String args[])
    {
        Scanner cin = new Scanner(System.in);

        int n = cin.nextInt(), k = cin.nextInt();

        BigInteger a[] = new BigInteger[n+1];

        for( int i=1; i<=n; i++ )
            a[i] = BigInteger.valueOf( 0 );
        a[0] = BigInteger.ONE;
        for( int i=1; i<=k; i++ )
            for( int j=i; j<=n; j++ )
                a[j] = a[j].add( a[j-i] );
        System.out.println( a[n] ); 
    }

}