HDU 1712 ACboy needs your help

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
动态规划入门题：dp[j] = max(dp[j], dp[j-k]+a[i][k]);
代码：

#include<stdio.h>
#include<string.h>
#define max 205
int main()
{
    //freopen("in.txt","r",stdin);
    int i,j,k,n,m,a[max][max],dp[max];
    while(scanf("%d%d",&n,&m),n||m)
    {
        memset(dp,0,sizeof(dp));
        for(i=1; i<=n; i++)
            for(j=1; j<=m; j++)
                scanf("%d",&a[i][j]);
        for(i=1; i<=n; i++)
            for(j=m; j>=1; j--)
                for(k=1; k<=j; k++)
                    if(dp[j]<dp[j-k]+a[i][k])dp[j]=dp[j-k]+a[i][k];
        printf("%d\n",dp[m]);
    }
    return 0;
}