hdu1078 dfs+dp（记忆化搜索）搜索一条递增路径，路径和最大，起点是（0,0）

#include<bits/stdc++.h>
using namespace std;
typedef unsigned int ui;
typedef long long ll;
typedef unsigned long long ull;
#define pf printf
#define prime1 1e9+7
#define prime2 1e9+9
#define scand(x) scanf("%llf",&x)
#define f(i,a,b) for(int i=a;i<=b;i++)
#define scan(a) scanf("%d",&a)
#define dbg(args) cout<<#args<<":"<<args<<endl;
#define pb(i) push_back(i)
#define ppb(x) pop_back(x)
#define maxn 1005
int n,k,t;
int Map[maxn][maxn],dp[maxn][maxn];
int dir[][2]={{0,1},{0,-1},{-1,0},{1,0}};
bool ok(int x,int y)
{
    if(x<0||x>=n||y<0||y>=n)return false;
    return true;
}
int dfs(int x,int y)
{
    if(dp[x][y])return dp[x][y];
    int temp=0;
    int M=0;
    f(i,0,3)
        f(j,1,k)
        {
            int xx=x+dir[i][0]*j;
            int yy=y+dir[i][1]*j;
            if(ok(xx,yy)&&Map[xx][yy]>Map[x][y])
            {
                temp=dfs(xx,yy);
                if(temp>dp[xx][yy])dp[xx][yy]=temp;
                if(dp[xx][yy]>M)M=dp[xx][yy];
            }
        }
        
    return dp[x][y]=Map[x][y]+M;
}
int main()
{
    std::ios::sync_with_stdio(false);
    while(scanf("%d%d",&n,&k)==2&&!(k==-1&&n==-1))
    {
        memset(dp,0,sizeof(dp));
        f(i,0,n-1)
            f(j,0,n-1)
            {
                scan(Map[i][j]);
            }
        dp[0][0]=dfs(0,0);
        pf("%d
",dp[0][0]);
    }
 }