HDU 1712 ACboy needs your help 分组背包

题目描述：

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

题目分析：

n堂课，m天时间，每一门课只能修1、2、3、、、或m天，每天都有一个特定的获益值。求如何安排这m天时间修这n门课。求获益值最大数。

分组背包，每一门课分一组，因为如果你选择在这门课修k天，就不能修其它天数，只能获得其k的获益值。

代码如下：

#include <iostream>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <algorithm>

using namespace std;

int dp[110];//dp[i]表示分配i天获得最大值
int a[110][110];
int m,n;

int main()
{
while(~scanf("%d%d",&n,&m) && (n||m))
{
for(int i=1; i<=n; i++)
for(int j=1; j<=m; j++)
scanf("%d",&a[i][j]);
memset(dp,0,sizeof(dp));
for(int i=1; i<=n; i++) //n组
{
for(int j=m; j>=1; j--) //剩余的天数
{
for(int k=1; k<=m; k++) //组内的标记
{
if (j>=k)
dp[j]=max(dp[j-k]+a[i][k],dp[j]);
}
}
}
printf("%d\n",dp[m]);
}
return 0;
}