题目描述

package dp;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class 数字组合 {

    /**
     * @param args
     * @throws IOException 
     */
    public static void main(String[] args) throws IOException {
        // TODO Auto-generated method stub
     BufferedReader bufferedReader=new BufferedReader(new InputStreamReader(System.in));
     String p[]=bufferedReader.readLine().split(" ");
     int n=Integer.parseInt(p[0]);
     int m=Integer.parseInt(p[1]);
     int a[]=new int [n+1];
     p=bufferedReader.readLine().split(" ");
     for(int i=1;i<=n;i++){
         a[i]=Integer.parseInt(p[i-1]);
     }
     int f[][]=new int [n+1][m+1];
     f[0][0]=1;
     for(int i=1;i<=n;i++){
         for(int j=0;j<=m;j++){
             f[i][j]=f[i-1][j];
             if(j>=a[i]){
                 f[i][j]+=f[i-1][j-a[i]];
             }
         }
     }
     System.out.println(f[n][m]);
    }

}