HDU1712ACboy needs your help【分组背包】

ACboy needs your help

Time Limit: 1000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 6249    Accepted Submission(s): 3430

Problem 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：

给你一个n*m的矩阵，行代表第i门课程，列代表修这门课程要花的时间天数，矩阵值代表得到的效益，输出最大效益。

输入：

输入n，m后输入n行m列的数代表效益

#include <iostream>
#include <cstring>
using namespace std;
int n,m;
int a[][];
int f[];
int main()
{
    while(cin>>n>>m)
    {
        if(n==&&m==)
            break;
        for(int i=;i<=n;i++)
            for(int j=;j<=m;j++)
                cin>>a[i][j];
        memset(f,,sizeof(f));
        for(int i=;i<=n;i++)
            for(int j=m;j>=;j--)
                for(int k=;k<=j;k++)
                    f[j]=max(f[j],f[j-k]+a[i][k]);
        cout<<f[m]<<endl;
    }
    return ;
}