ACboy needs your help hdu 分组背包问题

Description

ACboy has N courses this term, and he plans to spend at most M days on study.Of course,the profit he will gain from different course depending on the days he spend on it.How to arrange the M days for the N courses to maximize the profit? 

 

Input

The input consists of multiple data sets. A data set starts with a line containing two positive integers N and M, N is the number of courses, M is the days ACboy has.  Next follow a matrix A[i][j], (1<=i<=N<=100,1<=j<=M<=100).A[i][j] indicates if ACboy spend j days on ith course he will get profit of value A[i][j].  N = 0 and M = 0 ends the input. 

 

Output

For each data set, your program should output a line which contains the number of the max profit ACboy will gain. 

 

Sample Input

2 2 1 2 1 3 2 2 2 1 2 1 2 3 3 2 1 3 2 1 0 0

 

Sample Output

3 4 6

题意：  有n个课程，m天时间，接下来n*m的矩阵表示该课程花费1~m天时间所获能得的价值，求花费m天时间能获得的最大价值
   背包：
       分组背包模板题..将每一天看成一个组，每组只能选一个。

代码实现：

  #include<iostream>
  #include<cstdio>
  #include<algorithm>
  #include<cstring>
  using namespace std;
  int max(int a,int b)
  {
      return a>b?a:b;
  }
 int main()
 {
     int n,m,i,j,k,a[][],dp[];
     while(cin>>n>>m&&n&&m)
     {
         for(i=;i<=n;i++)
         for(j=;j<=m;j++)
         cin>>a[i][j];
         memset(dp,,sizeof(dp));
         for(i=;i<=n;i++)//分组
         for(j=m;j>;j--)//容量
         for(k=;k<=j;k++)//第i组数据
         dp[j]=max(dp[j],dp[j-k]+a[i][k]);
         cout<<dp[m]<<endl;
     }
     return ;
 }