思想

思想：类似于多重背包问题，多重背包是可以选第i个物品至多s[i]件，此题只允许选一件，每件体积和重量不同。

最终还是转化为01背包问题，选不选第x个的问题

java 代码

import java.io.*;
import java.lang.*;

class Main{

    static int n = 0, m = 0, N = 110;
    static int[][] f = new int[N][N];
    static int[][] v= new int[N][N], w = new int[N][N];
    static int[] s = new int[N];

    public static void main(String[] args)throws Exception{
        BufferedReader buf = new BufferedReader(new InputStreamReader(System.in));
        String[] params = buf.readLine().split(" ");
        n = Integer.valueOf(params[0]);
        m = Integer.valueOf(params[1]);

        for(int i = 1; i <= n; ++i){
            int cnt = Integer.valueOf(buf.readLine());
            s[i] = cnt;//记录每组的数量
            for(int j = 1; j <= cnt; ++j){
                String[] info = buf.readLine().split(" ");
                int a = Integer.valueOf(info[0]);
                int b = Integer.valueOf(info[1]);
                v[i][j] = a;
                w[i][j] = b;
            }
        }

        for(int i = 1; i <= n; ++i){
            for(int j = 0; j <= m; ++j){
                f[i][j] = f[i - 1][j];
                for(int x = 0; x <= s[i]; ++x){
                    if(v[i][x] <= j)
                        f[i][j] = Math.max(f[i][j], f[i - 1][j - v[i][x]] + w[i][x]);
                }
            }
        }
        System.out.print(f[n][m]);
    }
}