Description
1 @ US$3 + 1 @ US$2 1 @ US$3 + 2 @ US$1 1 @ US$2 + 3 @ US$1 2 @ US$2 + 1 @ US$1 5 @ US$1Write a program than will compute the number of ways FJ can spend N dollars (1 <= N <= 1000) at The Cow Store for tools on sale with a cost of $1..$K (1 <= K <= 100).
Input
Output
Sample Input
5 3
Sample Output
5
其中dp数组存贮组成当前数的个数
import java.math.*;
import java.util.*;
public class Main {
public static void main(String[] args) {
Scanner sca =new Scanner(System.in);
int k,n;
while(sca.hasNext())
{
n=sca.nextInt();
k=sca.nextInt();
BigInteger dp []=new BigInteger[1005];
for(int i=0;i<1005;i++)
dp[i]=BigInteger.ZERO;
dp[0]=BigInteger.ONE;
for(int i=1;i<=k;i++){
for(int j=0;j<=n;j++){
if(j>=i&&dp[j-i]!=BigInteger.ZERO){
dp[j]=dp[j].add(dp[j-i]);
}
}
}
System.out.println(dp[n]);
}
}
}
原文:http://blog.csdn.net/su20145104009/article/details/51539320