题目地址：http://acm.hdu.edu.cn/showproblem.php?pid=1078
#include <iostream>
#include <cstring>
#include <algorithm>
#include <cstdio>
using namespace std;
const int maxn=100+5;
int N,k;
int G[maxn][maxn],d[maxn][maxn];
const int dx[]={1,-1,0,0};
const int dy[]={0,0,1,-1};
bool inside(int x,int y){return x>=0&&x<N&&y>=0&&y<N;
}
int DP(int x,int y){int& ans=d[x][y];if(ans!=0) return ans;for(int i=1;i<=k;i++)for(int j=0;j<4;j++){int nx=x+i*dx[j];int ny=y+i*dy[j];if(inside(nx,ny)&&G[nx][ny]>G[x][y])ans=max(ans,DP(nx,ny));}ans+=G[x][y];return ans;
}
int main()
{while(cin>>N>>k){if(k==-1&&N==-1) break;for (int i = 0; i < N; ++i)for (int j = 0; j < N; ++j)scanf("%d",&G[i][j]);memset(d,0,sizeof(d));cout<<DP(0,0)<<endl;}return 0;
}